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Stoll TJ, Maddox RK. Enhanced Place Specificity of the Parallel Auditory Brainstem Response: An Electrophysiological Study. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.10.584313. [PMID: 38559254 PMCID: PMC10979863 DOI: 10.1101/2024.03.10.584313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Purpose This study investigates the effect of parallel stimulus presentation on the place specificity of the auditory brainstem response (ABR) in human listeners. Frequency-specific stimuli do not guarantee a response from the place on the cochlea corresponding only to that characteristic frequency - especially for brief and high-level stimuli. Adding masking noise yields responses that are more place specific, and a prior modeling study has suggested similar effects when multiple frequency-specific stimuli are presented in parallel. We tested this hypothesis experimentally here, comparing the place specificity of responses to serial and parallel stimuli at two stimulus frequencies and three stimulus rates. Methods Parallel ABR (pABR) stimuli were presented alongside high-pass filtered noise with a varied cutoff frequency. Serial presentation was also tested by isolating and presenting single-frequency stimulus trains from the pABR ensemble. Latencies of the ABRs were examined to assess place specificity of responses. Response bands were derived by subtracting responses from different high pass noise conditions. The response amplitude from each derived response band was then used to determine how much individual frequency regions of the auditory system were contributing to the overall response. Results We found that parallel presentation improves place specificity of ABRs for the lower stimulus frequency and at higher stimulus rates. At a higher stimulus frequency, serial and parallel presentation were equally place specific. Conclusion Parallel presentation can provide more place specific responses than serial for lower stimulus frequencies. The improvement increases with higher stimulus rates and is in addition to the pABR's primary benefit of faster test times.
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Affiliation(s)
- Thomas J Stoll
- University of Rochester, Department of Biomedical Engineering and
- University of Rochester, Department of Neuroscience
- University of Michigan, Kresge Hearing Research Institute
| | - Ross K Maddox
- University of Rochester, Department of Biomedical Engineering and
- University of Rochester, Department of Neuroscience
- University of Michigan, Kresge Hearing Research Institute
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Díaz M, Lucchetti F, Avan P, Giraudet F, Deltenre P, Nonclercq A. Preserved Auditory Steady State Response and Envelope-Following Response in Severe Brainstem Dysfunction Highlight the Need for Cross-Checking. Ear Hear 2024; 45:400-410. [PMID: 37828657 DOI: 10.1097/aud.0000000000001437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
OBJECTIVES Commercially available auditory steady state response (ASSR) systems are widely used to obtain hearing thresholds in the pediatric population objectively. Children are often examined during natural or induced sleep so that the recorded ASSRs are of subcortical origin, the inferior colliculus being often designated as the main ASSR contributor in these conditions. This report presents data from a battery of auditory neurophysiological objective tests obtained in 3 cases of severe brainstem dysfunction in sleeping children. In addition to ASSRs, envelope-following response (EFR) recordings designed to distinguish peripheral (cochlear nerve) from central (brainstem) were recorded to document the effect of brainstem dysfunction on the two types of phase-locked responses. DESIGN Results obtained in the 3 children with severe brainstem dysfunctions were compared with those of age-matched controls. The cases were identified as posterior fossa tumor, undiagnosed (UD), and Pelizaeus-Merzbacher-Like Disease. The standard audiological objective tests comprised tympanograms, distortion product otoacoustic emissions, click-evoked auditory brainstem responses (ABRs), and ASSRs. EFRs were recorded using horizontal (EFR-H) and vertical (EFR-V) channels and a stimulus phase rotation technique allowing isolation of the EFR waveforms in the time domain to obtain direct latency measurements. RESULTS The brainstem dysfunctions of the 3 children were revealed as abnormal (weak, absent, or delayed) ABRs central waves with a normal wave I. In addition, they all presented a summating and cochlear microphonic potential in their ABRs, coupled with a normal wave I, which implies normal cochlear and cochlear nerve function. EFR-H and EFR-V waveforms were identified in the two cases in whom they were recorded. The EFR-Hs onset latencies, response durations, and phase-locking values did not differ from their respective age-matched control values, indicating normal cochlear nerve EFRs. In contrast, the EFR-V phase-locking value and onset latency varied from their control values. Both patients had abnormal but identifiable and significantly phase-locked brainstem EFRs, even in a case with severely distorted ABR central waves. ASSR objective audiograms were recorded in two cases. They showed normal or slightly elevated (explained by a slight transmission loss) thresholds that do not yield any clue about their brainstem dysfunction, revealing the method's lack of sensitivity to severe brainstem dysfunction. CONCLUSIONS The present study, performed on 3 sleeping children with severe brainstem dysfunction but normal cochlear responses (cochlear microphonic potential, summating potential, and ABR wave I), revealed the differential sensitivity of three auditory electrophysiological techniques. Estimated thresholds obtained by standard ASSR recordings (cases UD and Pelizaeus-Merzbacher-Like Disease) provided no clue to the brainstem dysfunction clearly revealed by the click-evoked ABR. EFR recordings (cases posterior fossa tumor and UD) showed preserved central responses with abnormal latencies and low phase-locking values, whereas the peripheral EFR attributed to the cochlear nerve was normal. The one case (UD) for which the three techniques could be performed confirms this sensitivity gradient, emphasizing the need for applying the Cross-Check Principle by avoiding resorting to ASSR recording alone. The entirely normal EFR-H recordings observed in two cases further strengthen the hypothesis of its cochlear nerve origin in sleeping children.
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Affiliation(s)
- Macarena Díaz
- Bio-, Electro- and Mechanical Systems Department, Université Libre de Bruxelles, Brussels, Belgium
| | - Federico Lucchetti
- Critical and Extreme Security and Dependability Group (CritiX), Interdisciplinary Centre for Security, Reliability and Trust, Université du Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Paul Avan
- Department of Neurosensory Biophysics, Institut national de la santé et de la recherche médicale, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Fabrice Giraudet
- Department of Neurosensory Biophysics, Institut national de la santé et de la recherche médicale, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Paul Deltenre
- Laboratoire de Neurophysiologie Sensorielle et Cognitive, Department of Neurology, Brugmann Hospital, Brussels, Belgium
| | - Antoine Nonclercq
- Bio-, Electro- and Mechanical Systems Department, Université Libre de Bruxelles, Brussels, Belgium
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Zhang H, Xie J, Tao Q, Xiao Y, Cui G, Fang W, Zhu X, Xu G, Li M, Han C. The effect of motion frequency and sound source frequency on steady-state auditory motion evoked potential. Hear Res 2023; 439:108897. [PMID: 37871451 DOI: 10.1016/j.heares.2023.108897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/18/2023] [Accepted: 10/12/2023] [Indexed: 10/25/2023]
Abstract
The ability of humans to perceive motion sound sources is important for accurate response to the living environment. Periodic motion sound sources can elicit steady-state motion auditory evoked potential (SSMAEP). The purpose of this study was to investigate the effects of different motion frequencies and different frequencies of sound source on SSMAEP. The stimulation paradigms for simulating periodic motion of sound sources were designed utilizing head-related transfer function (HRTF) techniques in this study. The motion frequencies of the paradigm are set respectively to 1-10 Hz, 15 Hz, 20 Hz, 30 Hz, 40 Hz, 60 Hz, and 80 Hz. In addition, the frequencies of sound source of the paradigms were set to 500 Hz, 1000 Hz, 2000 Hz, 3000 Hz, and 4000 Hz at motion frequencies of 6 Hz and 40 Hz. Fourteen subjects with normal hearing were recruited for the study. SSMAEP was elicited by 500 Hz pure tone at motion frequencies of 1-10 Hz, 15 Hz, 20 Hz, 30 Hz, 40 Hz, 60 Hz, and 80 Hz. SSMAEP was strongest at motion frequencies of 6 Hz. Moreover, at 6 Hz motion frequency, the SSMAEP amplitude was largest at the tone frequency of 500 Hz and smallest at 4000 Hz. Whilst SSMAEP elicited by 4000 Hz pure tone was significantly the strongest at motion frequency of 40 Hz. SSMAEP can be elicited by periodic motion sound sources at motion frequencies up to 80 Hz. SSMAEP also has a strong response at lower frequency. Low-frequency pure tones are beneficial to enhance SSMAEP at low-frequency sound source motion, whilst high-frequency pure tones help to enhance SSMAEP at high-frequency sound source motion. The study provides new insight into the brain's perception of rhythmic auditory motion.
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Affiliation(s)
- Huanqing Zhang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Jun Xie
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China; School of Mechanical Engineering, Xinjiang University, Urumqi, China; National Key Laboratory of Human Factors Engineering, China Astronauts Research and Training Center, Beijing, China; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China.
| | - Qing Tao
- School of Mechanical Engineering, Xinjiang University, Urumqi, China.
| | - Yi Xiao
- National Key Laboratory of Human Factors Engineering, China Astronauts Research and Training Center, Beijing, China
| | - Guiling Cui
- National Key Laboratory of Human Factors Engineering, China Astronauts Research and Training Center, Beijing, China
| | - Wenhu Fang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Xinyu Zhu
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Guanghua Xu
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Min Li
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Chengcheng Han
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China
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DeJonckere PH, Lebacq J. Asymmetry of Occupational Noise Induced Hearing Loss: An Electrophysiological Approach. Int Arch Otorhinolaryngol 2023; 27:e499-e510. [PMID: 37564477 PMCID: PMC10411239 DOI: 10.1055/s-0042-1750766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 05/15/2022] [Indexed: 03/31/2023] Open
Abstract
Introduction The question as to whether occupational noise exposure causes symmetrical or asymmetrical hearing loss is still controversial and incompletely understood. Objective Two electrophysiological methods (cortical evoked response audiometry: CERA and auditory steady state responses: ASSR) were used to address this issue. Method 156 subjects with a well-documented history of noise exposure, a wide range of noise induced hearing loss (NIHL) and without middle ear pathology underwent both a CERA and an ASSR examination in the context of an exhaustive medicolegal expert assessment intended for possible compensation. Results Whatever the method (CERA or ASSR), the average electrophysiological hearing thresholds (1-2-3 kHz) are significantly worse in the left ear. The right - left differences in CERA and ASSR thresholds are strongly correlated with each other. No significant effect of frequency is found. No correlation is observed between right - left differences in hearing thresholds and either age or degree of hearing loss. Conclusion In NIHL, there is an actual average right - left difference of about 2.23 dB, i.e., 3.2%, the left ear being more impaired.
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Affiliation(s)
| | - Jean Lebacq
- University of Louvain, Neurosciences, Brussels, Belgium
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Zhang H, Xie J, Xiao Y, Cui G, Xu G, Tao Q, Gebrekidan YY, Yang Y, Ren Z, Li M. Steady-state auditory motion based potentials evoked by intermittent periodic virtual sound source and the effect of auditory noise on EEG enhancement. Hear Res 2023; 428:108670. [PMID: 36563411 DOI: 10.1016/j.heares.2022.108670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
Hearing is one of the most important human perception forms, and humans can capture the movement of sound in complex environments. On the basis of this phenomenon, this study explored the possibility of eliciting a steady-state brain response in an intermittent periodic motion sound source. In this study, a novel discrete continuous and orderly change of sound source positions stimulation paradigm was designed based on virtual sound using head-related transfer functions (HRTFs). And then the auditory motion stimulation paradigms with different noise levels were designed by changing the signal-to-noise ratio (SNR). The characteristics of brain response and the effects of different noises on brain response were studied by analyzing electroencephalogram (EEG) signals evoked by the proposed stimulation. Experimental results showed that the proposed paradigm could elicit a novel steady-state auditory evoked potential (AEP), i.e., steady-state motion auditory evoked potential (SSMAEP). And moderate noise could enhance SSMAEP amplitude and corresponding brain connectivity. This study enriches the types of AEPs and provides insights into the mechanism of brain processing of motion sound sources and the impact of noise on brain processing.
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Affiliation(s)
- Huanqing Zhang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Jun Xie
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China; National Key Laboratory of Human Factors Engineering, China Astronauts Research and Training Center, Beijing, China; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China; School of Mechanical Engineering, Xinjiang University, Urumqi, China.
| | - Yi Xiao
- National Key Laboratory of Human Factors Engineering, China Astronauts Research and Training Center, Beijing, China.
| | - Guiling Cui
- National Key Laboratory of Human Factors Engineering, China Astronauts Research and Training Center, Beijing, China
| | - Guanghua Xu
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Qing Tao
- School of Mechanical Engineering, Xinjiang University, Urumqi, China
| | | | - Yuzhe Yang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Zhiyuan Ren
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Min Li
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, China
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Perugia E, Marmel F, Kluk K. Feasibility of Diagnosing Dead Regions Using Auditory Steady-State Responses to an Exponentially Amplitude Modulated Tone in Threshold Equalizing Notched Noise, Assessed Using Normal-Hearing Participants. Trends Hear 2023; 27:23312165231173234. [PMID: 37384583 PMCID: PMC10336760 DOI: 10.1177/23312165231173234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 04/11/2023] [Accepted: 04/14/2023] [Indexed: 07/01/2023] Open
Abstract
The aim of this study was to assess feasibility of using electrophysiological auditory steady-state response (ASSR) masking for detecting dead regions (DRs). Fifteen normally hearing adults were tested using behavioral and electrophysiological tasks. In the electrophysiological task, ASSRs were recorded to a 2 kHz exponentially amplitude-modulated tone (AM2) presented within a notched threshold equalizing noise (TEN) whose center frequency (CFNOTCH) varied. We hypothesized that, in the absence of DRs, ASSR amplitudes would be largest for CFNOTCH at/or near the signal frequency. In the presence of a DR at the signal frequency, the largest ASSR amplitude would occur at a frequency (fmax) far away from the signal frequency. The AM2 and the TEN were presented at 60 and 75 dB SPL, respectively. In the behavioral task, for the same maskers as above, the masker level at which an AM and a pure tone could just be distinguished, denoted AM2ML, was determined, for low (10 dB above absolute AM2 threshold) and high (60 dB SPL) signal levels. We also hypothesized that the value of fmax would be similar for both techniques. The ASSR fmax values obtained from grand average ASSR amplitudes, but not from individual amplitudes, were consistent with our hypotheses. The agreement between the behavioral fmax and ASSR fmax was poor. The within-session ASSR-amplitude repeatability was good for AM2 alone, but poor for AM2 in notched TEN. The ASSR-amplitude variability between and within participants seems to be a major roadblock to developing our approach into an effective DR detection method.
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Affiliation(s)
- Emanuele Perugia
- Manchester Centre for Audiology and Deafness, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Frederic Marmel
- Manchester Centre for Audiology and Deafness, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Karolina Kluk
- Manchester Centre for Audiology and Deafness, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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Stoll TJ, Maddox RK. Enhanced Place Specificity of the Parallel Auditory Brainstem Response: A Modeling Study. Trends Hear 2023; 27:23312165231205719. [PMID: 37807857 PMCID: PMC10563492 DOI: 10.1177/23312165231205719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 09/13/2023] [Accepted: 09/19/2023] [Indexed: 10/10/2023] Open
Abstract
While each place on the cochlea is most sensitive to a specific frequency, it will generally respond to a sufficiently high-level stimulus over a wide range of frequencies. This spread of excitation can introduce errors in clinical threshold estimation during a diagnostic auditory brainstem response (ABR) exam. Off-frequency cochlear excitation can be mitigated through the addition of masking noise to the test stimuli, but introducing a masker increases the already long test times of the typical ABR exam. Our lab has recently developed the parallel ABR (pABR) paradigm to speed up test times by utilizing randomized stimulus timing to estimate the thresholds for multiple frequencies simultaneously. There is reason to believe parallel presentation of multiple frequencies provides masking effects and improves place specificity while decreasing test times. Here, we use two computational models of the auditory periphery to characterize the predicted effect of parallel presentation on place specificity in the auditory nerve. We additionally examine the effect of stimulus rate and level. Both models show the pABR is at least as place specific as standard methods, with an improvement in place specificity for parallel presentation (vs. serial) at high levels, especially at high stimulus rates. When simulating hearing impairment in one of the models, place specificity was also improved near threshold. Rather than a tradeoff, this improved place specificity would represent a secondary benefit to the pABR's faster test times.
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Affiliation(s)
- Thomas J. Stoll
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
- Del Monte Institute for Neuroscience, University of Rochester, Rochester, NY, USA
| | - Ross K. Maddox
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
- Del Monte Institute for Neuroscience, University of Rochester, Rochester, NY, USA
- Department of Neuroscience, University of Rochester, Rochester, NY, USA
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Anderson S, DeVries L, Smith E, Goupell MJ, Gordon-Salant S. Rate Discrimination Training May Partially Restore Temporal Processing Abilities from Age-Related Deficits. J Assoc Res Otolaryngol 2022; 23:771-786. [PMID: 35948694 PMCID: PMC9365219 DOI: 10.1007/s10162-022-00859-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 06/30/2022] [Indexed: 01/06/2023] Open
Abstract
The ability to understand speech in complex environments depends on the brain's ability to preserve the precise timing characteristics of the speech signal. Age-related declines in temporal processing may contribute to the older adult's experience of communication difficulty in challenging listening conditions. This study's purpose was to evaluate the effects of rate discrimination training on auditory temporal processing. A double-blind, randomized control design assigned 77 young normal-hearing, older normal-hearing, and older hearing-impaired listeners to one of two treatment groups: experimental (rate discrimination for 100- and 300-Hz pulse trains) and active control (tone detection in noise). All listeners were evaluated during pre- and post-training sessions using perceptual rate discrimination of 100-, 200-, 300-, and 400-Hz band-limited pulse trains and auditory steady-state responses (ASSRs) to the same stimuli. Training generalization was evaluated using several temporal processing measures and sentence recognition tests that included time-compressed and reverberant speech stimuli. Results demonstrated a session × training group interaction for perceptual and ASSR testing to the trained frequencies (100 and 300 Hz), driven by greater improvements in the training group than in the active control group. Further, post-test rate discrimination of the older listeners reached levels that were equivalent to those of the younger listeners at pre-test. Generalization was observed in significant improvement in rate discrimination of untrained frequencies (200 and 400 Hz) and in correlations between performance changes in rate discrimination and sentence recognition of reverberant speech. Further, non-auditory inhibition/attention performance predicted training-related improvement in rate discrimination. Overall, the results demonstrate the potential for auditory training to partially restore temporal processing in older listeners and highlight the role of cognitive function in these gains.
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Affiliation(s)
- Samira Anderson
- Department of Hearing and Speech Sciences, University of Maryland, College Park, 20742 USA
| | - Lindsay DeVries
- Department of Hearing and Speech Sciences, University of Maryland, College Park, 20742 USA
| | - Edward Smith
- Department of Hearing and Speech Sciences, University of Maryland, College Park, 20742 USA
| | - Matthew J. Goupell
- Department of Hearing and Speech Sciences, University of Maryland, College Park, 20742 USA
| | - Sandra Gordon-Salant
- Department of Hearing and Speech Sciences, University of Maryland, College Park, 20742 USA
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Comparison of non-invasive, scalp-recorded auditory steady-state responses in humans, rhesus monkeys, and common marmosets. Sci Rep 2022; 12:9210. [PMID: 35654875 PMCID: PMC9163194 DOI: 10.1038/s41598-022-13228-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 05/23/2022] [Indexed: 12/27/2022] Open
Abstract
Auditory steady-state responses (ASSRs) are basic neural responses used to probe the ability of auditory circuits to produce synchronous activity to repetitive external stimulation. Reduced ASSR has been observed in patients with schizophrenia, especially at 40 Hz. Although ASSR is a translatable biomarker with a potential both in animal models and patients with schizophrenia, little is known about the features of ASSR in monkeys. Herein, we recorded the ASSR from humans, rhesus monkeys, and marmosets using the same method to directly compare the characteristics of ASSRs among the species. We used auditory trains on a wide range of frequencies to investigate the suitable frequency for ASSRs induction, because monkeys usually use stimulus frequency ranges different from humans for vocalization. We found that monkeys and marmosets also show auditory event-related potentials and phase-locking activity in gamma-frequency trains, although the optimal frequency with the best synchronization differed among these species. These results suggest that the ASSR could be a useful translational, cross-species biomarker to examine the generation of gamma-band synchronization in nonhuman primate models of schizophrenia.
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Finneran JJ, Mulsow J, Strahan MG, Houser DS, Burkard RF. Output compensation of auditory brainstem responses in dolphins and sea lions. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 151:3070. [PMID: 35649923 DOI: 10.1121/10.0010389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Cochlear dispersion causes increasing delays between neural responses from high-frequency regions in the cochlear base and lower-frequency regions toward the apex. For broadband stimuli, this can lead to neural responses that are out-of-phase, decreasing the amplitude of farfield neural response measurements. In the present study, cochlear traveling-wave speed and effects of dispersion on farfield auditory brainstem responses (ABRs) were investigated by first deriving narrowband ABRs in bottlenose dolphins and California sea lions using the high-pass subtractive masking technique. Derived-band ABRs were then temporally aligned and summed to obtain the "stacked ABR" as a means of compensating for the effects of cochlear dispersion. For derived-band responses between 8 and 32 kHz, cochlear traveling-wave speeds were similar for sea lions and dolphins [∼2-8 octaves (oct)/ms for dolphins; ∼3.5-11 oct/ms for sea lions]; above 32 kHz, traveling-wave speed for dolphins increased up to ∼30 oct/ms. Stacked ABRs were larger than unmasked, broadband ABRs in both species. The amplitude enhancement was smaller in dolphins than in sea lions, and enhancement in both species appears to be less than reported in humans. Results suggest that compensating for cochlear dispersion will provide greater benefit for ABR measurements in species with better low-frequency hearing.
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Affiliation(s)
- James J Finneran
- United States Navy Marine Mammal Program, Naval Information Warfare Center Pacific Code 56710, 53560 Hull Street, San Diego, California 92152, USA
| | - Jason Mulsow
- National Marine Mammal Foundation, 2240 Shelter Island Drive #200, San Diego, California 92106, USA
| | - Madelyn G Strahan
- National Marine Mammal Foundation, 2240 Shelter Island Drive #200, San Diego, California 92106, USA
| | - Dorian S Houser
- National Marine Mammal Foundation, 2240 Shelter Island Drive #200, San Diego, California 92106, USA
| | - Robert F Burkard
- Department of Rehabilitation Science, University at Buffalo, 626 Kimball Tower, Buffalo, New York 14214, USA
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DeJonckere P, Lebacq J. The comparison of auditory behavioral and evoked potential responses (steady state and cortical) in subjects with occupational noise-induced hearing loss. J Otol 2021; 16:242-251. [PMID: 34548871 PMCID: PMC8438636 DOI: 10.1016/j.joto.2021.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/13/2021] [Accepted: 05/23/2021] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To define difference scores between PTA, ASSR and CERA thresholds in subjects with occupational NIHL. DESIGN 44 subjects undergoing a medico-legal expert assessment for occupational NIHL and fulfilling criteria of reliability were considered. Assessment included: PTA, 40 Hz binaural multiple ASSR and CERA (1-2-3 kHz). RESULTS The respective average difference scores (ASSR - PTA) for 1, 2 and 3 kHz are 13.01 (SD 10.19) dB, 12.72 (SD 8.81) dB and 10.38 (SD 8.19) dB. The average (CERA - ASSR) difference scores are 1.25 (SD 14.63) dB for 1 kHz (NS), 2.73 (SD 13.03) dB for 2 kHz (NS) and 4.51 (SD 12.18) dB for 3 kHz. The correlation between PTA and ASSR (0.82) is significantly stronger than that between PTA and CERA (0.71). In a given subject, PTA thresholds are nearly always lower (i.e., better) than ASSR thresholds, whatever the frequency (1-2-3 kHz) and the side (right - left). A significant negative correlation is found between the difference score (ASSR - PTA) and the degree of hearing loss. CONCLUSION ASSR outperforms CERA in a medicolegal context, although overestimating the behavioral thresholds by 10-13 dB.
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Affiliation(s)
- P.H. DeJonckere
- Federal Agency for Occupational Risks, Avenue de l’Astronomie, 1, B-1210, Bruxelles, Brussels, Belgium
| | - J. Lebacq
- Institute of Neurosciences, University of Louvain, Pasteur, Avenue Mounier, 53, B-1200, Bruxelles, Brussels, Belgium
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Objective frequency-specific hearing thresholds definition for medicolegal purposes in case of occupational NIHL: ASSR outperforms CERA. J Otol 2021; 16:210-219. [PMID: 34548866 PMCID: PMC8438637 DOI: 10.1016/j.joto.2021.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/13/2021] [Accepted: 02/18/2021] [Indexed: 11/24/2022] Open
Abstract
Audiological use of the 40 Hz-ASSR (auditory steady state responses) could be valuable for objectively estimating the frequency-specific threshold in adults undergoing an expertise examination for medicolegal and/or compensation purposes. The present prospective study was set up to clarify the relationship between the thresholds obtained by cortical evoked response audiometry (CERA) and by 40 Hz-ASSR, in the same ears, within a large homogeneous sample of 164 subjects (328 ears) with NIHL and well documented exposure to noise. All these subjects claimed financial compensation for occupational NIHL, and there was a suspicion of exaggeration of the reported NIHLs. ASSR thresholds show a good correlation with the CERA thresholds. However, a systematic shift is noticed, ASSR thresholds being on average (1–2 – 3 kHz) 4.38 dB lower (i.e. showing less hearing loss) than CERA thresholds. Moreover, the binaural multiple ASSR technique allows a considerable time gain when compared to the CERA.
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13
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Encina-Llamas G, Dau T, Epp B. On the use of envelope following responses to estimate peripheral level compression in the auditory system. Sci Rep 2021; 11:6962. [PMID: 33772043 PMCID: PMC7997911 DOI: 10.1038/s41598-021-85850-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 03/08/2021] [Indexed: 12/22/2022] Open
Abstract
Individual estimates of cochlear compression may provide complementary information to traditional audiometric hearing thresholds in disentangling different types of peripheral cochlear damage. Here we investigated the use of the slope of envelope following response (EFR) magnitude-level functions obtained from four simultaneously presented amplitude modulated tones with modulation frequencies of 80-100 Hz as a proxy of peripheral level compression. Compression estimates in individual normal hearing (NH) listeners were consistent with previously reported group-averaged compression estimates based on psychoacoustical and distortion-product oto-acoustic emission (DPOAE) measures in human listeners. They were also similar to basilar membrane (BM) compression values measured invasively in non-human mammals. EFR-based compression estimates in hearing-impaired listeners were less compressive than those for the NH listeners, consistent with a reduction of BM compression. Cochlear compression was also estimated using DPOAEs in the same NH listeners. DPOAE estimates were larger (less compressive) than EFRs estimates, showing no correlation. Despite the numerical concordance between EFR-based compression estimates and group-averaged estimates from other methods, simulations using an auditory nerve (AN) model revealed that compression estimates based on EFRs might be highly influenced by contributions from off-characteristic frequency (CF) neural populations. This compromises the possibility to estimate on-CF (i.e., frequency-specific or "local") peripheral level compression with EFRs.
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Affiliation(s)
- Gerard Encina-Llamas
- Hearing Systems Section, Department of Health Technology, Technical University of Denmark (DTU), 2800, Kongens Lyngby, Denmark.
| | - Torsten Dau
- Hearing Systems Section, Department of Health Technology, Technical University of Denmark (DTU), 2800, Kongens Lyngby, Denmark
| | - Bastian Epp
- Hearing Systems Section, Department of Health Technology, Technical University of Denmark (DTU), 2800, Kongens Lyngby, Denmark
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Parciauskaite V, Bjekic J, Griskova-Bulanova I. Gamma-Range Auditory Steady-State Responses and Cognitive Performance: A Systematic Review. Brain Sci 2021; 11:217. [PMID: 33579014 PMCID: PMC7916793 DOI: 10.3390/brainsci11020217] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/22/2021] [Accepted: 02/07/2021] [Indexed: 12/14/2022] Open
Abstract
The auditory steady-state response (ASSR) is a result of entrainment of the brain's oscillatory activity to the frequency and phase of temporally modulated stimuli. Gamma-range ASSRs are utilized to observe the dysfunctions of brain-synchronization abilities in neuropsychiatric and developmental disorders with cognitive symptoms. However, the link between gamma-range ASSRs and cognitive functioning is not clear. We systematically reviewed existing findings on the associations between gamma-range ASSRs and cognitive functions in patients with neuropsychiatric or developmental disorders and healthy subjects. The literature search yielded 1597 articles. After excluding duplicates and assessing eligibility, 22 articles were included. In healthy participants, the gamma-range ASSR was related to cognitive flexibility and reasoning as measured by complex tasks and behavioral indicators of processing speed. In patients with schizophrenia, the studies that reported correlations found a higher ASSR to be accompanied by better performance on short-term memory tasks, long-term/semantic memory, and simple speeded tasks. The main findings indicate that individual differences in the gamma-range ASSR reflect the level of attentional control and the ability to temporary store and manipulate the information, which are necessary for a wide range of complex cognitive activities, including language, in both healthy and impaired populations.
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Affiliation(s)
- Vykinta Parciauskaite
- Life Sciences Centre, Institute of Biosciences, Vilnius University, Sauletekio ave 7, LT-10257 Vilnius, Lithuania;
| | - Jovana Bjekic
- Human Neuroscience Group, Institute for Medical Research, University of Belgrade, Dr Subotića 4, 11000 Belgrade, Serbia;
| | - Inga Griskova-Bulanova
- Life Sciences Centre, Institute of Biosciences, Vilnius University, Sauletekio ave 7, LT-10257 Vilnius, Lithuania;
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Cevallos-Larrea PF, Frota SM, Ichinose RM, Tierra-Criollo CJ. Characterization of interstimulus interaction in the multiple auditory steady-state responses at high sound levels. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 148:1852. [PMID: 33138474 DOI: 10.1121/10.0002114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
Multiple auditory steady-state response (MASSR) is recommended to estimate hearing thresholds in difficult-to-test individuals. The multiple stimuli that evoke MASSR may present an interstimulus interaction (ISI) that is able to distort the generation of responses. No consensus exists on the effects of the ISI in MASSR when dealing with high sound level stimuli or cases of sensorineural hearing loss. This study investigated the effects of ISI on the amplitude and detectability of auditory steady-state responses, with a focus at and above 65 dB sound pressure level (SPL). Normal hearing (NH) and sensorineural hearing impaired (SNHI) adults were tested with different stimulus types [amplitude modulation (AM) One octave chirp (OC), and a weighted OC (WOC)], stimulus levels, and modalities (single or multiple stimuli). ISI typically attenuated response amplitude of a control stimulus caused by an interference stimulus one octave above the control stimulus. At and above 80 dB SPL, attenuations of around 50% decreased the number of detectable responses near SNHI thresholds, especially for OC and WOC. AM stimuli obtained a higher detection rate than OC and WOC when presented 10 dB above the behavioral hearing threshold of SNHI participants. Using OC in MASSR when assessing elevated thresholds might diminish accuracy on threshold estimation, and extend test duration.
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Affiliation(s)
- Pablo F Cevallos-Larrea
- Biomedical Engineering Research Group, Salesian Polytechnic University, Calle Vieja y Elia Liut, Cuenca 010107, Ecuador
| | - Silvana M Frota
- Medicine Faculty, Federal University of Rio de Janeiro, Avenue Carlos Chagas Filho 373, Rio de Janeiro 21.941-902, Brazil
| | - Roberto M Ichinose
- Biomedical Engineering Program, Federal University of Rio de Janeiro, Avenue Horácio Macedo 2030, Rio de Janeiro 21.941-590, Brazil
| | - Carlos J Tierra-Criollo
- Biomedical Engineering Program, Federal University of Rio de Janeiro, Avenue Horácio Macedo 2030, Rio de Janeiro 21.941-590, Brazil
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16
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Parthasarathy A, Bartlett EL, Kujawa SG. Age-related Changes in Neural Coding of Envelope Cues: Peripheral Declines and Central Compensation. Neuroscience 2019; 407:21-31. [DOI: 10.1016/j.neuroscience.2018.12.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 12/22/2022]
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17
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Vanheusden FJ, Chesnaye MA, Simpson DM, Bell SL. Envelope frequency following responses are stronger for high-pass than low-pass filtered vowels. Int J Audiol 2019; 58:355-362. [DOI: 10.1080/14992027.2018.1562243] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Frederique J. Vanheusden
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
- School of Science and Technology, Nottingham Trent University, Clifton Campus, Nottingham, UK
| | - Michael A. Chesnaye
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - David M. Simpson
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - Steven L. Bell
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
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Easwar V, Banyard A, Aiken SJ, Purcell DW. Phase‐locked responses to the vowel envelope vary in scalp‐recorded amplitude due to across‐frequency response interactions. Eur J Neurosci 2018; 48:3126-3145. [DOI: 10.1111/ejn.14161] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 08/22/2018] [Accepted: 08/28/2018] [Indexed: 01/26/2023]
Affiliation(s)
- Vijayalakshmi Easwar
- Communication Sciences & Disorders and Waisman CenterUniversity of Wisconsin Madison Wisconsin
- National Center for AudiologyWestern University London Ontario Canada
| | - Ashlee Banyard
- Communication Sciences and DisordersWestern University London Ontario Canada
| | - Steven J. Aiken
- School of Human Communication DisordersDalhousie University Halifax Nova Scotia Canada
| | - David W. Purcell
- National Center for AudiologyWestern University London Ontario Canada
- Communication Sciences and DisordersWestern University London Ontario Canada
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Synaptopathy in the Aging Cochlea: Characterizing Early-Neural Deficits in Auditory Temporal Envelope Processing. J Neurosci 2018; 38:7108-7119. [PMID: 29976623 DOI: 10.1523/jneurosci.3240-17.2018] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 12/12/2022] Open
Abstract
Aging listeners, even in the absence of overt hearing loss measured as changes in hearing thresholds, often experience impairments processing temporally complex sounds such as speech in noise. Recent evidence has shown that normal aging is accompanied by a progressive loss of synapses between inner hair cells and auditory nerve fibers. The role of this cochlear synaptopathy in degraded temporal processing with age is not yet understood. Here, we used population envelope following responses, along with other hair cell- and neural-based measures from an age-graded series of male and female CBA/CaJ mice to study changes in encoding stimulus envelopes. By comparing responses obtained before and after the application of the neurotoxin ouabain to the inner ear, we demonstrate that we can study changes in temporal processing on either side of the cochlear synapse. Results show that deficits in neural coding with age emerge at the earliest neural stages of auditory processing and are correlated with the degree of cochlear synaptopathy. These changes are seen before losses in neural thresholds and particularly affect the suprathreshold processing of sound. Responses obtained from more central sources show smaller differences with age, suggesting compensatory gain. These results show that progressive cochlear synaptopathy is accompanied by deficits in temporal coding at the earliest neural generators and contribute to the suprathreshold sound processing deficits observed with age.SIGNIFICANCE STATEMENT Aging listeners often experience difficulty hearing and understanding speech in noisy conditions. The results described here suggest that age-related loss of cochlear synapses may be a significant contributor to those performance declines. We observed aberrant neural coding of sounds in the early auditory pathway, which was accompanied by and correlated with an age-progressive loss of synapses between the inner hair cells and the auditory nerve. Deficits first appeared before changes in hearing thresholds and were largest at higher sound levels relevant to real world communication. The noninvasive tests described here may be adapted to detect cochlear synaptopathy in the clinical setting.
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Jaeger M, Bleichner MG, Bauer AKR, Mirkovic B, Debener S. Did You Listen to the Beat? Auditory Steady-State Responses in the Human Electroencephalogram at 4 and 7 Hz Modulation Rates Reflect Selective Attention. Brain Topogr 2018; 31:811-826. [DOI: 10.1007/s10548-018-0637-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 02/23/2018] [Indexed: 01/23/2023]
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21
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Guérit F, Marozeau J, Epp B. Linear combination of auditory steady-state responses evoked by co-modulated tones. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:EL395. [PMID: 29092566 DOI: 10.1121/1.5007757] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Up to medium intensities and in the 80-100-Hz region, the auditory steady-state response (ASSR) to a multi-tone carrier is commonly considered to be a linear sum of the dipoles from each tone specific ASSR generator. Here, this hypothesis was investigated when a unique modulation frequency is used for all carrier components. Listeners were presented with a co-modulated dual-frequency carrier (1 and 4 kHz), from which the modulator starting phase Φi of the 1-kHz component was systematically varied. The results support the hypothesis of a linear superposition of the dipoles originating from different frequency specific ASSR generators.
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Affiliation(s)
- François Guérit
- Hearing Systems group, Department of Electrical Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark , ,
| | - Jeremy Marozeau
- Hearing Systems group, Department of Electrical Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark , ,
| | - Bastian Epp
- Hearing Systems group, Department of Electrical Engineering, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark , ,
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22
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Race N, Lai J, Shi R, Bartlett EL. Differences in postinjury auditory system pathophysiology after mild blast and nonblast acute acoustic trauma. J Neurophysiol 2017; 118:782-799. [PMID: 28275059 PMCID: PMC5539456 DOI: 10.1152/jn.00710.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 03/02/2017] [Accepted: 03/02/2017] [Indexed: 01/05/2023] Open
Abstract
Hearing difficulties are the most commonly reported disabilities among veterans. Blast exposures during explosive events likely play a role, given their propensity to directly damage both peripheral (PAS) and central auditory system (CAS) components. Postblast PAS pathophysiology has been well documented in both clinical case reports and laboratory investigations. In contrast, blast-induced CAS dysfunction remains understudied but has been hypothesized to contribute to an array of common veteran behavioral complaints, including learning, memory, communication, and emotional regulation. This investigation compared the effects of acute blast and nonblast acoustic impulse trauma in adult male Sprague-Dawley rats. An array of audiometric tests were utilized, including distortion product otoacoustic emissions (DPOAE), auditory brain stem responses (ABR), middle latency responses (MLR), and envelope following responses (EFRs). Generally, more severe and persistent postinjury central auditory processing (CAP) deficits were observed in blast-exposed animals throughout the auditory neuraxis, spanning from the cochlea to the cortex. DPOAE and ABR results captured cochlear and auditory nerve/brain stem deficits, respectively. EFRs demonstrated temporal processing impairments suggestive of functional damage to regions in the auditory brain stem and the inferior colliculus. MLRs captured thalamocortical transmission and cortical activation impairments. Taken together, the results suggest blast-induced CAS dysfunction may play a complementary pathophysiological role to maladaptive neuroplasticity of PAS origin. Even mild blasts can produce lasting hearing impairments that can be assessed with noninvasive electrophysiology, allowing these measurements to serve as simple, effective diagnostics.NEW & NOTEWORTHY Blasts exposures often produce hearing difficulties. Although cochlear damage typically occurs, the downstream effects on central auditory processing are less clear. Moreover, outcomes were compared between individuals exposed to the blast pressure wave vs. those who experienced the blast noise without the pressure wave. It was found that a single blast exposure produced changes at all stages of the ascending auditory path at least 4 wk postblast, whereas blast noise alone produced largely transient changes.
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Affiliation(s)
- Nicholas Race
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
- School of Medicine, Indiana University, Indianapolis, Indiana
| | - Jesyin Lai
- Purdue University Inderdisciplinary Life Science (PULSe) Program, Purdue University, West Lafayette, Indiana; and
| | - Riyi Shi
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
- Purdue University Inderdisciplinary Life Science (PULSe) Program, Purdue University, West Lafayette, Indiana; and
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana
| | - Edward L Bartlett
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana;
- Purdue University Inderdisciplinary Life Science (PULSe) Program, Purdue University, West Lafayette, Indiana; and
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23
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Finneran JJ, Mulsow J, Houser DS, Schlundt CE. Neural representation of the self-heard biosonar click in bottlenose dolphins (Tursiops truncatus). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 141:3379. [PMID: 28599518 PMCID: PMC5438311 DOI: 10.1121/1.4983191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 04/18/2017] [Accepted: 04/26/2017] [Indexed: 06/07/2023]
Abstract
The neural representation of the dolphin broadband biosonar click was investigated by measuring auditory brainstem responses (ABRs) to "self-heard" clicks masked with noise bursts having various high-pass cutoff frequencies. Narrowband ABRs were obtained by sequentially subtracting responses obtained with noise having lower high-pass cutoff frequencies from those obtained with noise having higher cutoff frequencies. For comparison to the biosonar data, ABRs were also measured in a passive listening experiment, where external clicks and masking noise were presented to the dolphins and narrowband ABRs were again derived using the subtractive high-pass noise technique. The results showed little change in the peak latencies of the ABR to the self-heard click from 28 to 113 kHz; i.e., the high-frequency neural responses to the self-heard click were delayed relative to those of an external, spectrally "pink" click. The neural representation of the self-heard click is thus highly synchronous across the echolocation frequencies and does not strongly resemble that of a frequency modulated downsweep (i.e., decreasing-frequency chirp). Longer ABR latencies at higher frequencies are hypothesized to arise from spectral differences between self-heard clicks and external clicks, forward masking from previously emitted biosonar clicks, or neural inhibition accompanying the emission of clicks.
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Affiliation(s)
- James J Finneran
- U.S. Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific Code 71510, 53560 Hull Street, San Diego, California 92152, USA
| | - Jason Mulsow
- National Marine Mammal Foundation; 2240 Shelter Island Drive #200, San Diego, California 92106, USA
| | - Dorian S Houser
- National Marine Mammal Foundation; 2240 Shelter Island Drive #200, San Diego, California 92106, USA
| | - Carolyn E Schlundt
- Harris Corporation, 4045 Hancock Street #210, San Diego, California 92110, USA
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Lu TM, Wu FW, Chang H, Lin HC. Using click-evoked auditory brainstem response thresholds in infants to estimate the corresponding pure-tone audiometry thresholds in children referred from UNHS. Int J Pediatr Otorhinolaryngol 2017; 95:57-62. [PMID: 28576534 DOI: 10.1016/j.ijporl.2017.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 02/01/2017] [Accepted: 02/03/2017] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To examine whether behavioral pure-tone audiometry (PTA) thresholds in children can be accurately estimated from the corresponding infants' click-evoked auditory brainstem response (ABR) thresholds through a retrospective review of data from a universal newborn hearing screening (UNHS) program in Taiwan. METHOD According to medical records from Mackay Memorial Hospital, Taipei Hospital District, 45,450 newborns received hearing screening during January 1999-December 2011. Among these newborns, 104 (82, both ears; 22, one ear; total, 186 ears) received regular follow-up and were recruited as subjects. The relationship between infant click-evoked ABR thresholds and the corresponding child PTA thresholds was determined through Pearson correlation coefficient and linear regression analyses. RESULTS The correlation coefficient between click-evoked ABR thresholds and behavioral PTA thresholds at the average of frequencies of 1-4 and 2-4 kHz was 0.76 and 0.76, respectively. Linear regression analysis showed that behavioral audiometry thresholds at the average of frequencies of 1-4 and 2-4 kHz were accurately estimated from click-evoked ABR thresholds in 57% and 58% children, respectively. CONCLUSION Click-evoked ABR testing is a reliable tool to cautiously estimate behavioral PTA thresholds at the average of frequencies of 1-4 and 2-4 kHz. For accurately performing hearing aid fitting and auditory rehabilitation in congenitally deaf infants, a combination of frequency-specific tone-burst ABR and click-evoked ABR should be used.
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Affiliation(s)
- Tsun-Min Lu
- Department of Otolaryngology, Mackay Memorial Hospital, Taipei, Taiwan
| | - Fang-Wei Wu
- Department of Otolaryngology, Mackay Memorial Hospital, Taipei, Taiwan; Department of Speech and Hearing Disorders and Sciences, National Taipei College of Nursing, Taiwan
| | - Hsiuwen Chang
- Department of Audiology and Speech Language Pathology, Mackay Medical College, Taipei, Taiwan
| | - Hung-Ching Lin
- Department of Otolaryngology, Mackay Memorial Hospital, Taipei, Taiwan; Department of Audiology and Speech Language Pathology, Mackay Medical College, Taipei, Taiwan; Department of Medicine, Mackay Medical College, Taipei, Taiwan.
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25
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Yuvaraj P, Jayaram M. Audiological Profile of Adult Persons with Auditory Neuropathy Spectrum Disorders. J Audiol Otol 2016; 20:158-167. [PMID: 27942602 PMCID: PMC5144811 DOI: 10.7874/jao.2016.20.3.158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 07/20/2016] [Accepted: 08/03/2016] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND AND OBJECTIVES The auditory profile of a large number of persons with late onset auditory neuropathy spectrum disorder (ANSD) is recently described in the Indian context. The purpose of study was 1) to profile data on routine audiological parameters, cortical evoked potentials, and temporal processing, 2) to analyze the benefit from hearing aids for persons with ANSD, and 3) to understand the association between benefit from hearing aids and auditory profile. SUBJECTS AND METHODS Thirty-eight adults with late onset ANSD and a matched group of 40 normally hearing adults participated in the study. Basic audiological tests, recording of cortical evoked potentials, and temporal processing tests were carried out on both groups of participant while only persons with ANSD were fitted with hearing aid. RESULTS Subjects in the two groups were significantly different on all the audiological parameters. ANSD group seemed to benefit from hearing aids variably. The mean amplitude of N2 was significantly different between normally-hearing participants and patients with ANSD. CONCLUSIONS Residual temporal processing, particularly amplitude modulation detection seems to be associated with benefit from hearing aids in patients with ANSD.
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Affiliation(s)
- Pradeep Yuvaraj
- Department of Speech-Language Pathology & Audiology, National Institute of Mental Health & Neurosciences, Bangalore, India
| | - Mannarukrishnaiah Jayaram
- Department of Speech-Language Pathology & Audiology, National Institute of Mental Health & Neurosciences, Bangalore, India
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26
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Rampp S, Rensch L, Simmermacher S, Rahne T, Strauss C, Prell J. Intraoperative auditory steady-state monitoring during surgery in the cerebellopontine angle for estimation of postoperative hearing classes. J Neurosurg 2016; 127:559-568. [PMID: 27739939 DOI: 10.3171/2016.7.jns16460] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Brainstem auditory evoked potentials (BAEPs) have been used for intraoperative monitoring of the auditory nerve for many years. However, BAEPs yield limited information about the expected postoperative hearing quality and speech perception. The auditory steady-state response (ASSR) enables objective audiograms to be obtained in patients under anesthesia. These ASSRs could be used for intraoperative estimation of hearing classes to improve the postoperative outcome and quality of life. Studies investigating the clinical use of ASSRs during total intravenous anesthesia are currently lacking. The work presented in this article therefore investigates the application of ASSRs for intraoperative estimation of hearing classes. METHODS In 43 patients undergoing surgery for vestibular schwannoma, ASSR measurements were performed at the beginning and end of the surgical procedure. ASSR stimuli consisted of 80-dB hearing level amplitude-modulated tones with 5-minute duration, 90-Hz modulation, and 3 different carrier frequencies: 500, 1000, and 2000 Hz. Stimulation was performed unilaterally with and without contralateral masking, using single and combined carriers. Evoked responses were recorded and analyzed in the frequency domain. ASSRs were compared with extraoperative hearing classes and BAEPs using ANOVA, correlation, and receiver operating characteristic statistics. RESULTS ASSRs yielded high and consistent area under the curve (AUC) values (mean 0.83) and correlation values (mean -0.63), indicating reliable prediction of hearing classes. Analysis of BAEP amplitude changes showed lower AUC (mean 0.79) and correlation values (0.63, 0.37, and 0.50 for Waves I, III, and V, respectively). Latencies showed low AUC values (mean 0.6) and no significant correlation. Combination of several carriers for simultaneous evaluation reduced ASSR amplitudes and respective AUC values. Contralateral masking did not show a significant effect. CONCLUSIONS ASSRs robustly estimate hearing class in patients under total intravenous anesthesia, even when using short measurement durations. The method provides a diagnostic performance that exceeds conventional BAEP monitoring and enables objective and automated evaluation. On the basis of these findings, continuous intraoperative auditory monitoring could become a promising alternative or adjunct to BAEPs.
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Affiliation(s)
| | | | | | - Torsten Rahne
- Otorhinolaryngology, Head and Neck Surgery, University Hospital Halle (Saale), Germany
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27
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Finneran JJ, Mulsow J, Houser DS, Burkard RF. Place specificity of the click-evoked auditory brainstem response in the bottlenose dolphin (Tursiops truncatus). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:2593. [PMID: 27794308 DOI: 10.1121/1.4964274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Cochlear place specificity of the auditory brainstem response (ABR) was investigated in five bottlenose dolphins by measuring ABRs to broadband clicks presented simultaneously with masking noise having various high-pass cutoff frequencies. Click and noise stimuli were digitally compensated to account for the transmitting response of the piezoelectric transducers and any multipath propagation effects to achieve "white" or "pink" spectral characteristics. Narrowband evoked responses were derived by sequentially subtracting responses obtained with noise at lower high-pass cutoff frequencies from those obtained with noise having higher cutoff frequencies. The results revealed little contribution to the click-evoked brainstem response from frequency bands below 10 kHz and, in dolphins with full hearing bandwidth, the largest amplitude derived band evoked responses were obtained from the highest frequency bands. Narrowband latencies decreased with increasing frequency and were adequately fit with a power function exhibiting relatively large change in latency with frequency below ∼30 kHz and little change above ∼30 kHz. These data demonstrate that frequency bands below ∼10 kHz do not substantively contribute to the farfield ABR in the bottlenose dolphin when using place-specific approaches such as high-pass subtractive-masking techniques.
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Affiliation(s)
- James J Finneran
- U.S. Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific Code 71510, 53560 Hull Street, San Diego, California 92152, USA
| | - Jason Mulsow
- National Marine Mammal Foundation, 2240 Shelter Island Drive #200, San Diego, California 92106, USA
| | - Dorian S Houser
- National Marine Mammal Foundation, 2240 Shelter Island Drive #200, San Diego, California 92106, USA
| | - Robert F Burkard
- Department of Rehabilitation Science, University at Buffalo, 510 Kimball Tower, Buffalo, New York 14214, USA
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Torres-Fortuny A, Hernández-Pérez H, Ramírez B, Alonso I, Eimil E, Guerrero-Aranda A, Mijares E. Comparing auditory steady-state responses amplitude evoked by simultaneous air- and bone-conducted stimulation in newborns. Int J Audiol 2016; 55:375-9. [DOI: 10.3109/14992027.2016.1159341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
| | - Heivet Hernández-Pérez
- Speech and Hearing Sciences Department. Cuban Neuroscience Centre, La Habana, Cuba,
- Department of Linguistics. Faculty of Human Sciences, Macquarie University, Sydney, NSW, Australia,
| | | | - Ileana Alonso
- Maternity Hospital “Ramón González Coro”, La Habana, Cuba,
| | - Eduardo Eimil
- Speech and Hearing Sciences Department. Cuban Neuroscience Centre, La Habana, Cuba,
| | | | - Eleina Mijares
- Speech and Hearing Sciences Department. Cuban Neuroscience Centre, La Habana, Cuba,
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Kaf WA, Mohamed ES, Elshafiey H. 40-Hz Sinusoidal Auditory Steady-State Response and Tone Burst Auditory Brainstem Response Using a Kalman Filter to Determine Thresholds Pre- and Post-Myringotomy With Grommet Tube in Children With Mild, Low-Frequency Conductive Hearing Loss. Am J Audiol 2016; 25:41-53. [PMID: 26990054 DOI: 10.1044/2015_aja-15-0052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 12/22/2015] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Accurate estimation of mild, low-frequency hearing loss is difficult in young children. This study aimed to determine the accuracy of 40-Hz sinusoidal auditory steady-state response (sASSR) compared with tone burst auditory brainstem response (TB-ABR) to detect mild, low-frequency hearing loss in children with otitis media with effusion and to measure postoperative thresholds. METHODS Thresholds at 500 and 4000 Hz were measured behaviorally and electrophysiologically using TB-ABR and 40-Hz sASSR with a Kalman filter in 26 children with otitis media with effusion. Recording was conducted preoperatively and postoperatively while children were actively awake. Repeated measures mixed analyses of variance were conducted to determine effects among measures and the two test frequencies. RESULTS Both 40-Hz sASSR and TB-ABR accurately detected preoperative and postoperative thresholds and were within 5-10 dB of the behavioral thresholds at 4000 Hz. At 500 Hz, the mean 40-Hz sASSR threshold was only 5 dB above the behavioral thresholds and 18 dB better than the 500-Hz ABR threshold. Positive correlations were found but not between 40-sASSR and TB-ABR at 500 Hz. Also, the interrater judgment of the response was better for sASSR (89%) than TB-ABR (83%). CONCLUSION The 40-Hz sASSR is more accurate than TB-ABR in determining a mild, low-frequency threshold.
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Towards an optimal paradigm for intraoperative auditory nerve monitoring with auditory steady state responses. J Clin Monit Comput 2016; 31:123-134. [PMID: 26852030 DOI: 10.1007/s10877-016-9837-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
Abstract
Auditory steady state responses (ASSR) may offer an alternative to brainstem auditory evoked potentials for monitoring of the auditory nerve during surgical procedures. In the current study, we evaluated the influence of noise on ASSR characteristics in total intravenous anesthesia (TIVA). Simulated ASSR in real noise recorded during surgery under TIVA were constructed with known parameters. Influence of amplitude, modulation frequency, averaging sweeps and detection threshold on ASSR were evaluated. High amplitude, more sweeps and a liberal threshold facilitated detection. High amplitude ASSR (80 nV) were detected in up to 45 % with 16 s of data, in 80-90 % with 112 s. Near-threshold ASSR were detected in 0.8-25 %. False positives ranged between 0.3 and 10.3 %. Number of sweeps did not influence false positives. Amplitude errors varied between -61 and +39 % and improved with more averages but not with different thresholds. Modulation rate demonstrated the strongest influence on all parameters. 110 Hz yielded best, 90 Hz the worst results. Choice of parameters strongly influences detection and characteristics of ASSR. Optimal parameters enabled detection after 16 s in 45 %. Due to specific noise characteristics, modulation has a critical impact, which is currently not sufficiently recognized in ASSR studies.
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Effect of Stimulus Level and Bandwidth on Speech-Evoked Envelope Following Responses in Adults With Normal Hearing. Ear Hear 2015; 36:619-34. [DOI: 10.1097/aud.0000000000000188] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sardari S, Jafari Z, Haghani H, Talebi H. Hearing aid validation based on 40 Hz auditory steady-state response thresholds. Hear Res 2015; 330:134-41. [PMID: 26385486 DOI: 10.1016/j.heares.2015.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 08/30/2015] [Accepted: 09/08/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND AIM Aided thresholds can be used for prediction of success of hearing aids and to choose between hearing aids and cochlear implants. This study aimed to compare characteristics of aided and unaided auditory steady-state responses (ASSRs). METHODS A total of 30 moderate to profoundly hearing-impaired subjects participated in this study. The subjects underwent acoustic immittance, behavioral audiometry, and ASSR with the modulation rate of 40 Hz, first without a hearing aid and then with a hearing aid. Sixteen people with normal hearing and 17 people with severe hearing loss were included in biological calibration of the sound field. RESULTS There was a significant difference between unaided behavioral and ASSR thresholds in all test frequencies (mean difference of unaided behavioral ASSR thresholds: 6.19 dB; P = 0.02 at 500 Hz, P < 0.001 at 1000 and 2000 Hz, and P = 0.02 for 4000 Hz). There was also a significant difference between aided behavioral and ASSR thresholds at 1000 and 2000 Hz (P < 0.001) but not at 500 (P = 0.14) and 4000 (P = 0.23) Hz (mean difference of behavioral ASSR thresholds was 4.33 dB). Despite observing any unaided responses, aided thresholds could be recorded in some severe to profoundly hearing-impaired subjects. The number of recordable thresholds was directly related to speech clarity and speech-reading ability. Multi-frequency stimulation elevated the ASSR threshold, especially for the higher frequencies and in the aided condition. CONCLUSION Functional and ASSR gains show less difference than threshold data. Therefore, comparing gains instead of thresholds is more accurate for validation of hearing aids. The probability of success of hearing aids appears to be poor if ASSRs (especially aided ones) cannot be recorded. If special care is taken in the fitting of hearing aids and the testing conditions, aided ASSR testing could be a useful tool for validation of hearing aids and the cochlear implant decision-making process.
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Affiliation(s)
- Sara Sardari
- Department of Audiology, Faculty of Rehabilitation, Tehran University of Medical Sciences, Iran.
| | - Zahra Jafari
- Department of Basic Sciences in Rehabilitation, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran; Canadian Center for Behavioral Neuroscience (CCBN), Lethbridge University, Lethbridge, Alberta, Canada.
| | - Hamid Haghani
- Department of Statistics and Mathematics, Faculty of Management, Tehran University of Medical Sciences, Iran
| | - Hossain Talebi
- Department of Audiology, Faculty of Rehabilitation, Isfahan University of Medical Sciences, Isfahan, Iran
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de Oliveira Beck RM, Ramos BF, Grasel SS, Ramos HF, de Moraes MFBB, de Almeida ER, Bento RF. Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects✩✩Please cite this article as: Beck RM, Ramos BF, Grasel SS, Ramos HF, Moraes MF, Almeida ER, et al. Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects. Braz J Otorhinolaryngol. 2014;80:35-40. Braz J Otorhinolaryngol 2014; 80:35-40. [PMID: 24626890 PMCID: PMC9443973 DOI: 10.5935/1808-8694.20140009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 07/30/2013] [Indexed: 11/22/2022] Open
Abstract
Introdução As respostas auditivas de estado estável permitem avaliar de forma objetiva limiares auditivos frequência-específica. A audiometria tonal é o exame padrão-ouro; no entanto, nem sempre pode ser conclusiva, principalmente em crianças e adultos não colaborativos. Objetivo Comparar os limiares auditivos da RAEE aos da audiometria tonal em indivíduos com audição normal. Materiais e métodos Foram incluídos neste estudo prospectivo de corte transversal 26 adultos (52 orelhas), de ambos os gêneros, com audiometria normal e sem queixas otológicas. Os pacientes foram submetidos a anamnese, otomicroscopia, audiometria e imitanciometria. A seguir, realizou-se avaliação de respostas auditivas de estado estável. Os resultados obtidos foram analisados estatisticamente e comparados entre si. Resultados A diferença entre os limiares (em dB NA) obtidos em ambos os exames para cada frequência testada foi de 7,12 dB para 500 Hz; 7,6 dB para 1000 Hz; 8,27 dB para 2000 Hz e 9,71 dB para 4000 Hz, com limiares mais elevados na RAEE, em todas as frequências. Não houve diferença estatística entre as médias para cada frequência testada. Conclusão Os limiares obtidos na RAEE foram comparáveis aos da audiometria tonal em indivíduos normouvintes; entretanto, não deve ser usado como único método de avaliação auditiva. © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Publicado por Elsevier Editora Ltda. Todos os direitos reservados.
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Affiliation(s)
| | - Bernardo Faria Ramos
- Department of Otorhinolaryngology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
| | - Signe Schuster Grasel
- Department of Otorhinolaryngology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
| | - Henrique Faria Ramos
- Hospital Universitário Cassiano Antônio de Moraes, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil
| | | | - Edigar Rezende de Almeida
- Department of Otorhinolaryngology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
| | - Ricardo Ferreira Bento
- Department of Otorhinolaryngology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
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Papakonstantinou A, Kollmeier B, Riedel H. Ipsi- and contralateral interaction in the 40 Hz auditory steady state responses (ASSRs) with two carriers at 60 dB SPL. Int J Audiol 2013; 52:626-35. [DOI: 10.3109/14992027.2013.799785] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Slow cortical potentials and amplification-part I: n1-p2 measures. Int J Otolaryngol 2012; 2012:921513. [PMID: 23118756 PMCID: PMC3483828 DOI: 10.1155/2012/921513] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Accepted: 09/10/2012] [Indexed: 11/17/2022] Open
Abstract
Slow cortical potentials (SCPs) are currently of great interest in the hearing aid fitting process for infants; however, there is conflicting evidence in the literature concerning the use of SCPs for this purpose. The current study investigated SCP amplitudes and latencies in young normal-hearing listeners in response to a 60 ms duration tonal stimulus (1000 Hz) presented at three intensities (30, 50, and 70 dB SPL) in aided and unaided conditions using three hearing aids (Analog, DigitalA, and DigitalB) with two gain settings (20 and 40 dB). Results showed that SCP amplitudes were smaller for the digital hearing aids compared with the analog hearing aid, and none of the hearing aids resulted in a reliable increase in response amplitude relative to the unaided across conditions. SCP latencies in analog conditions were not significantly different from latencies in the unaided conditions; however, both digital hearing aids resulted in significantly delayed SCP latencies. The results of the current study (as well as several previous studies) indicate that the SCP may not accurately reflect the amplified stimulus expected from the prescribed hearing aids. Thus, “aided-SCP” results must be interpreted with caution, and more research is required concerning possible clinical use of this technique.
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Multiple-ASSR Interactions in Adults with Sensorineural Hearing Loss. Int J Otolaryngol 2012; 2012:802715. [PMID: 23049561 PMCID: PMC3463185 DOI: 10.1155/2012/802715] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 07/26/2012] [Indexed: 11/17/2022] Open
Abstract
The multiple auditory steady-state response (multiple-ASSR) technique, where thresholds for up to 8 frequencies (4 in each ear) are obtained simultaneously, is currently of great interest for audiometric assessment of infants. Although threshold estimates using the multiple-ASSR appear to be reasonably accurate, it is not currently known whether it is more efficient to use multiple stimuli or single stimuli when testing individuals with sensorineural hearing loss (SNHL). The current study investigated the effect of single versus multiple simultaneous stimuli on the 80- and 40-Hz ASSRs in adults with normal hearing or SNHL. Results showed significant interactions (i.e., decreased amplitudes) for both ASSRs going from single to multiple stimuli in one ear. Going from multiple one ear to multiple two ears did not further reduce the amplitude of the 80-Hz ASSR. At the 40-Hz rate, however, there was a further amplitude decrease going from one-ear multiple to two-ear multiple stimuli. Importantly, these interactions did not differ between the normal-hearing and SNHL groups. Although supportive of the multiple-ASSR technique, there are likely situations where it is more efficient to use single stimuli. Future studies are required to assess these interactions in infants with varying degrees and configurations of hearing loss.
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Mühler R, Mentzel K, Verhey J. Fast hearing-threshold estimation using multiple auditory steady-state responses with narrow-band chirps and adaptive stimulus patterns. ScientificWorldJournal 2012; 2012:192178. [PMID: 22619622 PMCID: PMC3349325 DOI: 10.1100/2012/192178] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 12/22/2011] [Indexed: 12/13/2022] Open
Abstract
This paper describes the estimation of hearing thresholds in normal-hearing and hearing-impaired subjects on the basis of multiple-frequency auditory steady-state responses (ASSRs). The ASSR was measured using two new techniques: (i) adaptive stimulus patterns and (ii) narrow-band chirp stimuli. ASSR thresholds in 16 normal-hearing and 16 hearing-impaired adults were obtained simultaneously at both ears at 500, 1000, 2000, and 4000 Hz, using a multiple-frequency stimulus built up of four one-octave-wide narrow-band chirps with a repetition rate of 40 Hz. A statistical test in the frequency domain was used to detect the response. The recording of the steady-state responses was controlled in eight independent recording channels with an adaptive, semiautomatic algorithm. The average differences between the behavioural hearing thresholds and the ASSR threshold estimate were 10, 8, 13, and 15 dB for test frequencies of 500, 1000, 2000, and 4000 Hz, respectively. The average overall test duration of 18.6 minutes for the threshold estimations at the four frequencies and both ears demonstrates the benefit of an adaptive recording algorithm and the efficiency of optimised narrow-band chirp stimuli.
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Affiliation(s)
- Roland Mühler
- Department of Experimental Audiology, Otto-von-Guericke University Magdeburg, Leipziger Street 44, 39120 Magdeburg, Germany.
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Brennan SK, Brooke RE, Stevens JC. The effect of varying stimulus phase between frequency and amplitude modulation on auditory steady-state responses in neonates. Int J Audiol 2011; 51:116-23. [DOI: 10.3109/14992027.2011.617392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Ishida IM, Cuthbert BP, Stapells DR. Multiple auditory steady state response thresholds to bone conduction stimuli in adults with normal and elevated thresholds. Ear Hear 2011; 32:373-81. [PMID: 21206364 DOI: 10.1097/aud.0b013e318201c1e5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Auditory steady state responses (ASSRs) to multiple air conduction (AC) stimuli modulated at ∼80 Hz have been shown to provide reasonable estimates of the behavioral audiogram. To distinguish the type of hearing loss (i.e., conductive, sensorineural, or mixed), bone conduction (BC) results are necessary. There are few BC-ASSR data, especially for individuals with hearing loss. The present studies aimed to (1) determine multiple ASSR thresholds to BC stimuli in adults with normal hearing, masker-simulated hearing loss, and sensorineural hearing loss (SNHL) and (2) determine how well BC-ASSR distinguishes normal versus elevated thresholds to BC stimuli in adults with normal hearing or SNHL. DESIGN Multiple ASSR and behavioral thresholds for BC stimuli were determined in two studies. Study A assessed 16 normal-hearing adults with relatively flat threshold elevations produced by 50, 60, and 70 dB SPL AC masking noise, as well as no masking. Study B assessed 10 adults with normal hearing and 40 adults with SNHL. In both studies, the multiple (500 to 4000 Hz) ASSR stimuli were modulated between 77 and 101 Hz and varied in intensity from 0 to 50 dB HL in 10-dB steps. Stimuli were presented using a B71 bone oscillator held on the temporal bone by an elastic band while participants relaxed or slept. RESULTS Study A: Correlations (r) between behavioral and ASSR thresholds for all conditions combined were 0.77, 0.87, 0.90, and 0.87 for 500, 1000, 2000, and 4000 Hz, respectively. ASSR minus behavioral threshold difference scores for all frequencies combined for the no-masker, 50, 60, and 70 dB SPL masker conditions were 14.3 ± 9.2, 12.1 ± 10.4, 12.7 ± 7.7, and 11.4 ± 8.1 dB, respectively. Study B: The difference scores for 500, 1000, 2000, and 4000 Hz were, on average, 15.7 ± 12.3, 10.3 ± 10.7, 9.7 ± 10.3, and 5.7 ± 7.9 dB, respectively, with correlations of 0.73, 0.84, 0.87, and 0.94 for the normal-hearing and SNHL groups combined. The ASSR minus behavioral difference scores were significantly larger for 500 Hz and significantly smaller for 4000 Hz compared with 1000 and 2000 Hz. Across all frequencies, the BC-ASSR correctly classified 89% of thresholds as "normal" or "elevated" (92% correct for 1000, 2000, and 4000 Hz). CONCLUSIONS The threshold difference scores and correlations in individuals with SNHL are similar to those in normal listeners with simulated SNHL. These difference scores are also similar to those shown by previous studies for the AC-ASSR in individuals with SNHL, at least for 1000 to 4000 Hz. The BC-ASSR provides a reasonably good estimate of BC behavioral threshold in adults, especially between 1000 and 4000 Hz. Further research is required in infants with hearing loss.
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Affiliation(s)
- Ieda M Ishida
- School of Audiology and Speech Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
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Using the auditory steady state response to record response amplitude curves. A possible fast objective method for diagnosing dead regions. Ear Hear 2011; 32:485-97. [PMID: 21285879 DOI: 10.1097/aud.0b013e31820a77e2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To assess a novel objective method of measuring response amplitude curves (RACs) using auditory steady state responses in adults. DESIGN RACs were recorded in 20 normal-hearing adults. The RACs were measured by recording the changes in the amplitude of the auditory steady state response in the presence of (1) swept frequency narrowband masking noise and (2) fixed narrowband masking noise. RESULTS The mean recorded RAC tip frequency for a 2-kHz signal was 2250 Hz for the swept masker method and 2239 Hz for the fixed masker method. The estimated repeatability coefficients, calculated using an assumed mean difference of zero, were 389 Hz for the swept method and 342 Hz for the fixed method. CONCLUSIONS These initial results indicate that the swept- and fixed-masking methods appear to be viable and fast ways to record RACs in normal-hearing adults. Further work is needed to further optimize the accuracy of the tip frequency estimation and to establish the normative range of tip frequencies over a wide range of test frequencies in normal-hearing and hearing-impaired subjects.
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Effect of Varying Phase Between Frequency and Amplitude Modulation on Bone Conduction Auditory Steady State Responses. Ear Hear 2010; 31:815-24. [DOI: 10.1097/aud.0b013e3181e508f6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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D’haenens W, Vinck BM, Maes L, Bockstael A, Keppler H, Philips B, Swinnen F, Dhooge I. Determination and evaluation of clinically efficient stopping criteria for the multiple auditory steady-state response technique. Clin Neurophysiol 2010; 121:1267-78. [PMID: 20457007 DOI: 10.1016/j.clinph.2010.03.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 02/08/2010] [Accepted: 03/08/2010] [Indexed: 11/26/2022]
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Interaction among the components of multiple auditory steady-state responses: enhancement in tinnitus patients, inhibition in controls. Neuroscience 2010; 167:540-53. [PMID: 20152886 DOI: 10.1016/j.neuroscience.2010.02.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2009] [Revised: 01/20/2010] [Accepted: 02/01/2010] [Indexed: 10/19/2022]
Abstract
Amplitude and phase of steady-state signals recorded in response to amplitude-modulated (AM) sine tones vary over time, suggesting that the steady-state response (SSR) reflects not only stimulus input but also its interaction with other input streams or internally generated signals. Alterations of the interaction between simultaneous SSRs associated with tinnitus were studied by recording the magnetic field evoked by AM-tones with one of three carrier and one of three modulation frequencies. Single AM-tones were presented in single presentation mode and superpositions of three AM-tones differing in carrier and modulation frequency in multiple presentation mode. Modulation frequency-specific SSR components were recovered by bandpass filtering. Compared with single mode, in multiple mode SSR amplitude was reduced in healthy controls, but increased in tinnitus patients. Thus, while in controls multiple response components seem to reciprocally inhibit one another, in tinnitus reciprocal facilitation seems to predominate. Reciprocal inhibition was unrelated to the phase coherence among SSR components, but was correlated with the frequency of phase slips, indicating that the lateral interaction among SSR components acts in a quasi-paroxysmal manner and manifests itself in terms of a random train of phase reset events. Phase slips were more frequent in patients than controls both in single and multiple mode. Together, these findings indicate that lateral or surround inhibition of single units in auditory cortex is reduced and suggest that in-field inhibition is increased in tinnitus.
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Abstract
In contrast to the transient (N1-P2) and steady-state (<20 Hz) cortical responses, neither the transient (auditory brain stem response) nor the steady-state (80 Hz) brain stem responses show the binaural masking level difference (BMLD). This study determined behavioral and 40-Hz auditory steady-state response (ASSR) BMLDs for both signal and noise interaural inversions. Results showed clear behavioral BMLD but no 40-Hz ASSR BMLD. However, ASSR amplitudes were significantly smaller in dichotic compared with diotic conditions. Thus, although 40-Hz ASSR thresholds do not reflect the BMLD, the amplitude suppression under dichotic conditions may be a precursor to the subsequent <20-Hz ASSR and behavioral BMLDs.
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van der Reijden CS, Mens LHM, Snik AFM. Frequency-specific objective audiometry: Tone-evoked brainstem responses and steady-state responses to 40 Hz and 90 Hz amplitude modulated stimuli. Int J Audiol 2009; 45:40-5. [PMID: 16562563 DOI: 10.1080/14992020500258537] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Tone-evoked Auditory Brainstem Responses (tone-burst ABRs) and Auditory Steady-State Responses (ASSRs) with 40 or 90 Hz amplitude modulation (AM) were compared, using the same equipment and recording parameters, to determine which of these three methods most accurately approached the behavioural hearing thresholds in response to 500 Hz and 2000 Hz stimuli in eleven awake adults with normal hearing. Estimates of the thresholds obtained with the three methods were 10, 18, and 26 dB SL at 500 Hz; and 10, 12, and 22 dB SL at 2000 Hz; using 40 Hz ASSR, 90 Hz ASSR, and tone-burst ABR, respectively. ASSRs with 40 Hz AM stimuli produced significantly better results (lowest thresholds with SD=0), whereas the wave-V analysis on the tone-burst ABR produced the poorest results. In the averaged ABRs, a robust steady-state potential was also visible. Analysis of those steady-state responses showed estimated thresholds of 13 and 14 dB SL (at 500 and 2000 Hz, respectively), thus considerably better than the estimated thresholds from the wave-V analysis. It is concluded that the 40 Hz ASSR showed superior results, especially at 500 Hz.
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D'haenens W, Dhooge I, De Vel E, Maes L, Bockstael A, Vinck BM. Auditory steady-state responses to MM and exponential envelope AM2/FM stimuli in normal-hearing adults. Int J Audiol 2009; 46:399-406. [PMID: 17654081 DOI: 10.1080/14992020701347329] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The present study utilized a commercially available multiple auditory steady-state response (ASSR) system to test normal hearing adults (n=55). The primary objective was to evaluate the impact of the mixed modulation (MM) and the novel proposed exponential AM(2)/FM stimuli on the signal-to-noise ratio (SNR) and threshold estimation accuracy, through a within-subject comparison. The second aim was to establish a normative database for both stimulus types. The results demonstrated that the AM(2)/FM and MM stimulus had a similar effect on the SNR, whereas the ASSR threshold results revealed that the AM(2)/FM produced better thresholds than the MM stimulus for the 500, 1000, and 4000 Hz carrier frequency. The mean difference scores to tones of 500, 1000, 2000, and 4000 Hz were for the MM stimulus: 20+/-12, 14+/-9, 10+/-8, and 12+/-8 dB; and for the AM(2)/FM stimulus: 18+/-13, 12+/-8, 11+/-8, and 10+/-8 dB, respectively. The current research confirms that the AM(2)/FM stimulus can be used efficiently to test normal hearing adults.
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Frequency tuning curves derived from auditory steady state evoked potentials: a proof-of-concept study. Ear Hear 2009; 30:43-53. [PMID: 19125026 DOI: 10.1097/aud.0b013e31818fbb7a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Assess the feasibility of drawing tuning curves from the masking function of steady state potentials. Develop a noninvasive tool for research applications on cochlear frequency selectivity in sedated animals. Obtain pilot human data validating auditory steady state evoked potential-derived (ASSEP) tuning curves against psychophysical data. DESIGN ASSEP tuning curves were drawn in 10 Beagle puppies and six human adults using amplitude-modulated probes. Two probe frequencies (1 and 2 kHz) were used in dogs and only one (2 kHz) in humans. The modulation rates of the two probes were set to 81 and 88 Hz, respectively. Psychophysical tuning curves were obtained in 12 normal human subjects using the same maskers and either a pure-tone or an amplitude-modulated probe to verify if the latter had a specific effect on tuning curve parameters. Six of these 12 subjects participated in the electrophysiologic measurements. For each tuning curve, the intensity of the narrowband masker required just to mask the fixed probe was plotted for different masker center frequencies. Masker center frequencies extended to about half an octave above and an octave below the probe frequencies in 100-Hz steps. Tuning curve width (Q10 dB values), high- and low-frequency slopes (in dB/octave) and the masker frequency yielding the lowest masking threshold (maximal masker frequency) were computed. Canine Q10 dB values obtained were compared with those published for several species with other techniques. For humans, ASSEP and psychophysical tuning curves were directly compared in the same subjects and with published data. RESULTS In dogs, the ASSEP method yielded reproducible tuning curves with qualitative and quantitative parameters similar to other physiologic measures of tuning obtained in various animals. Q10 dB values were greater at 2 than at 1 kHz, reflecting the well-known correlation between sharpness of tuning and central frequency. In humans, ASSEP Q10 dB values were slightly smaller than the psychophysical ones, but were greater by a factor of 2 than those obtained with previously published electrophysiologic procedures. In both species, detuning-a shift of the tip of the curve away from the probe frequency-was frequently observed as upward shifts with a maximal value of 200 Hz. Human psychophysical tuning curves also showed a certain amount of upward detuning. The intraindividual comparison of the two types of probes performed on human subjects with the psychophysical method did not indicate a specific effect of the amplitude-modulated probe on the curve parameters. Neither did the intraindividual comparisons indicate that an amplitude-modulated probe per se promoted detuning. Detuning has been observed with several other techniques and is usually attributed to nonlinear interactions between masker and probe in simultaneous masking. CONCLUSIONS The results demonstrate the feasibility of measuring realistic ASSEP tuning curves in sedated dogs and in sleeping human adults. The ASSEP tuning curves exhibit a series of classical features similar to those obtained with time-honored methods. These results pave the way for the development of a noninvasive electrophysiologic method for tuning curve recording and its applications in noncooperative experimental animals or clinical subjects.
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[Audiometric thresholds estimated by auditory steady-state responses. Influence of EEG amplitude and test duration on accuracy]. HNO 2008; 57:44-50. [PMID: 19093093 DOI: 10.1007/s00106-008-1849-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To examine the influence of electroencephalogram (EEG) amplitude, test duration, and residual noise on the definition of threshold criteria for auditory steady-state responses (ASSR) in three representative populations. METHODS EEG recordings from 61 patients, 11 sedated babies, and 53 relaxed volunteers were used in an offline analysis that calculated the mean EEG amplitude and the time course of residual noise. Additionally, the time course of residual noise and the test duration for a fixed level of residual noise were estimated from the mean EEG amplitude using the "square root of N" law of averaging. RESULTS A strong correlation between measured and predicted residual noise was found in all three groups. The mean EEG amplitude as well as the predicted test duration for a fixed residual noise level differed significantly among the three groups, with EEG amplitudes in clinical patients being four times greater than in relaxed volunteers. CONCLUSIONS The strong correlation between EEG amplitude, test duration, and residual noise in ASSR recordings allows for the prediction of individual test duration or residual noise levels in advanced testing algorithms. This study found that high mean EEG amplitudes in awake patients considerably reduce the accuracy of hearing thresholds estimated by ASSR.
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Kumar K, Sinha SK, Bhat JS. Tone-evoked brainstem responses and auditory steady state responses to 40hz and 80hz amplitude modulated stimuli with different frequencies - a comparative study. Indian J Otolaryngol Head Neck Surg 2008; 60:142-6. [PMID: 23120523 DOI: 10.1007/s12070-008-0058-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
UNLABELLED Tone burst evoked auditory brainstem responses and auditory steady state responses with 40 or > 80 Hz modulation can be used to determine frequency specific threshold. AIM The present study was taken up to check for the efficacy of estimating hearing thresholds by tone burst ABR and ASSR. The frequency effect (low, mid and high) on estimating the threshold was also focused upon. METHODS 20 normal hearing adults (40 ears) in the age range of 16 to 30 years participated in the study. The pure tone audiometry and immittance was initially done. Subsequently, tone-burst ABR, 80Hz ASSR and 40Hz ASSR to estimate the threshold with three frequencies 500Hz (low), 2000Hz (mid) and 4000Hz (high) was done. The data was analyzed statistically using pair sample t-test. RESULTS ASSR threshold for 80Hz and 40Hz was almost comparable. ASSR was superior to estimate the threshold than tone-burst ABR. For the low frequency the discrepancy between the behavioral threshold and frequency-specific evoked audiometry was more when compared to mid and high frequency. CONCLUSION Present study showed that steady-state responses were efficient means of threshold detection than visual detection of ABR wave-V. In awake adult subjects, 40Hz and 80Hz amplitude modulated produced similar results. For the threshold estimation ASSR was better than tone-burst ABR.
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Affiliation(s)
- Kaushlendra Kumar
- Department of Audiology & Speech Language Pathology, KMC (A Unit of Manipal University), Mangalore-1, India
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Abstract
OBJECTIVE To investigate the effect of brief-tone stimulus duration on the amplitude of the brain stem auditory steady-state response (ASSR), both in single- and multiple-stimulus conditions. DESIGN In Experiment 1, the primary stimuli were Blackman-windowed 500- and 2000-Hz brief tones presented using repetition rates of 79 and 83 Hz, respectively. Stimuli had durations ranging from 0.5 to 12 msec. In the single-stimulus condition, these two stimuli were presented dichotically, whereas in the four-stimulus multiple-stimulus condition, instead of being presented alone, each stimulus was combined with three interfering stimuli, which were also Blackman-windowed brief tones spaced one octave apart, and presented at rates of 77 to 96 Hz. In Experiment 2, the effect of brief-tone duration and the effect of interfering stimuli were further studied by systematically removing interfering stimuli from the multiple stimuli, with the goal of determining which specific stimuli in the multiple stimuli were responsible for the interference. In both experiments, stimuli were presented at 75 ppe dB SPL. The subjects were normal-hearing adults, who relaxed or slept during the recording sessions. RESULTS Experiment 1: ASSR amplitudes increased as stimulus duration decreased in the single-stimulus condition, for both 500 and 2000 Hz. However, amplitudes did not significantly increase until stimuli were quite brief (2 msec for 2000 Hz; 6 msec for 500 Hz). In the four-stimulus multiple-stimulus condition, the pattern of amplitude increase with decreasing stimulus duration at 2000 Hz was similar to that in the single-stimulus condition, although amplitudes at all durations were reduced. However, for 500-Hz stimuli in the four-stimulus multiple-stimulus condition, ASSR amplitudes showed no change as stimulus duration decreased. Experiment 2: for 2000-Hz stimuli, the 4000-Hz interfering stimuli resulted in the largest change in amplitude, the 1000-Hz interfering stimuli had a small effect, and the 500-Hz interfering stimuli had no effect. For 500-Hz stimuli, the 1000-Hz interfering stimuli had the greatest effect, the 2000-Hz interfering stimuli the next largest, and the 4000-Hz interfering stimuli a small effect. The interference effects for 500-Hz stimuli occurred only for brief (< or =6 msec) stimuli, with no effects of the interfering stimuli when the 500-Hz stimuli were 8 or 12 msec in duration. CONCLUSION Although brief tones may result in larger-amplitude ASSRs, their duration must be quite brief (not more than three to four cycles) to show a significant amplitude increase. Moreover, when presented together with other stimuli in the multiple-stimulus technique, response interference reduces the amplitudes of ASSRs, and for 500 Hz removes the amplitude gain normally seen with decreasing duration. Brief-tone stimuli, therefore, may not be optimal for ASSR threshold estimation, especially because of the compromise in frequency specificity accompanying the use of very brief tones.
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