The effect of brief-tone stimulus duration on the brain stem auditory steady-state response

Auditory steady state responses elicited by silent gaps embedded within a broadband noise

Background

Auditory temporal processing plays an important role in speech comprehension. Usually, behavioral tests that require subjects to detect silent gaps embedded within a continuous sound are used to assess the ability of auditory temporal processing in humans. To evaluate auditory temporal processing objectively, the present study aimed to measure the auditory steady state responses (ASSRs) elicited by silent gaps of different lengths embedded within a broadband noise. We presented a broadband noise with 40-Hz silent gaps of 3.125, 6.25, and 12.5 ms.

Results

The 40-Hz silent gaps of 3.125, 6.25, and 12.5 ms elicited clear ASSRs. Longer silent gaps elicited larger ASSR amplitudes and ASSR phases significantly differed between conditions.

Conclusion

The 40 Hz gap-evoked ASSR contributes to our understanding of the neural mechanisms underlying auditory temporal processing and may lead to the development of objective measures of auditory temporal acuity in humans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12868-022-00712-0.

Characterization of interstimulus interaction in the multiple auditory steady-state responses at high sound levels

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.

Slow cortical potentials and amplification-part I: n1-p2 measures

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.

Multiple-ASSR Interactions in Adults with Sensorineural Hearing Loss

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.

[On the terminology of auditory steady-state responses. What differentiates steady-state and transient potentials?]

BACKGROUND

Recording human auditory steady-state responses (ASSR) at different frequencies allows objective assessment of auditory thresholds. Common practice has been to record ASSR to pure tones that are sinusoidally modulated in amplitude and frequency. Recently, optimized chirp stimuli have been proposed to evoke transient as well as steady-state responses. Because of the resulting uncertainty about the different methods, this paper aims to reconsider the terminology of transient and steady-state responses.

METHOD

Two experiments demonstrate the smooth transition between transient and steady-state responses. In experiment 1, click-evoked auditory brainstem responses (ABR) were recorded over a wide range of stimulus repetition rates (24/s to 72/s). In experiment 2, auditory steady-state responses were recorded for the same stimulus repetition rates, using three different stimulus types: an amplitude modulated 1-kHz tone (AM), a 1-kHz tone-burst (TB) and a flat-spectrum chirp.

RESULTS

Experiment 1 demonstrates the merging of the typical ABR wave complexes at higher repetition rates, forming a steady-state response. This effect can only be observed if the time window is extended far beyond the window traditionally used for clinical ABR recordings. Experiment 2 reveals similar ASSR amplitude spectra regardless of the stimulus type and repetition rate used.

CONCLUSION

Steady-state responses can be evoked for a large variety of stimulus types and repetition rates. Thus, from a clinician's point of view, steady-state responses cannot be considered a new type of evoked responses. They differ from transient responses primarily in the frequency response method and the longer timeframe required.

Auditory steady-state response in children with cochlear hearing loss

BACKGROUND

auditory steady-state response (ASSR) is indicated as a promising technique in the assessment of the hearing status of children.

AIM

to investigate the level of agreement between the results of the ASSR and the visual reinforcement audiometry (VRA) in a group of children, thus examining the clinical applicability of this technique in hearing assessment of children.

METHOD

participants were 14 children with ages between 4 and 36 months (mean 16 months) with the diagnosis of cochlear hearing loss. The ASSR was recorded in the frequencies of 0.5, 1, 2 and 4kHz for multiple simultaneous stimulation and the results were compared with the visual reinforcement audiometry (VRA).

RESULTS

the intraclass correlation coefficients between ASSR and VRA were 0.90, 0.93, 0.93 and 0.89 respectively for the frequencies of 0.5, 1, 2 and 4kHz, indicating a strong correlation between the techniques.

CONCLUSION

the ASSR can provide accurate information to support the selection of hearing aids for children when it is not possible to perform the VRA.

Bone-conducted hearing assessment with 80-Hz multiple auditory steady-state responses to brief tones in adults with normal hearing

OBJECTIVE

To investigate interactions (if any) in the bone-conduction auditory steady-state response (BC ASSR) between multiple brief tones presented simultaneously.

METHODS

500-, 1,000-, 2,000-, and 4,000-Hz brief tones, repeated at a rate of 77-101 Hz, were presented using a B-71 vibrator. BC ASSR thresholds and amplitudes at 50 dB nHL were measured in two conditions where the stimulus was either presented alone or together with other stimuli.

RESULTS

Significantly larger amplitudes in the single-stimulus condition were found at 50 dB nHL. However, there was no significant threshold difference between single- and multiple-stimulus conditions. The BC ASSR thresholds (means ± SD) at 500, 1,000, 2,000, and 4,000 Hz were 96.7 ± 9.7, 75.3 ± 11.5, 65.6 ± 7.4, and 57.8 ± 7.2 dB re 1 μN ppe, respectively.

CONCLUSION

Interactions occurred in the multiple-stimulus condition at high presentation levels, but not at threshold levels. The results of the present study imply that BC ASSR thresholds to multiple brief-tone stimuli can be assessed at the same time, at least in normal-hearing adults.

Longitudinal assessment of air conduction audiograms in a phase III clinical trial of difluoromethylornithine and sulindac for prevention of sporadic colorectal adenomas

A phase III clinical trial assessed the recurrence of adenomatous polyps after treatment for 36 months with difluoromethylornithine (DFMO) plus sulindac or matched placebos. Temporary hearing loss is a known toxicity of treatment with DFMO, thus a comprehensive approach was developed to analyze serial air conduction audiograms. The generalized estimating equation method estimated the mean difference between treatment arms with regard to change in air conduction pure tone thresholds while accounting for within-subject correlation due to repeated measurements at frequencies. Based on 290 subjects, there was an average difference of 0.50 dB between subjects treated with DFMO plus sulindac compared with those treated with placebo (95% confidence interval, -0.64 to 1.63 dB; P = 0.39), adjusted for baseline values, age, and frequencies. In the normal speech range of 500 to 3,000 Hz, an estimated difference of 0.99 dB (-0.17 to 2.14 dB; P = 0.09) was detected. Dose intensity did not add information to models. There were 14 of 151 (9.3%) in the DFMO plus sulindac group and 4 of 139 (2.9%) in the placebo group who experienced at least 15 dB hearing reduction from baseline in 2 or more consecutive frequencies across the entire range tested (P = 0.02). Follow-up air conduction done at least 6 months after end of treatment showed an adjusted mean difference in hearing thresholds of 1.08 dB (-0.81 to 2.96 dB; P = 0.26) between treatment arms. There was no significant difference in the proportion of subjects in the DFMO plus sulindac group who experienced clinically significant hearing loss compared with the placebo group. The estimated attributable risk of ototoxicity from exposure to the drug is 8.4% (95% confidence interval, -2.0% to 18.8%; P = 0.12). There is a <2 dB difference in mean threshold for patients treated with DFMO plus sulindac compared with those treated with placebo.