Functional outcomes for speech-in-noise intelligibility of NAL-NL2 and DSL v.5 prescriptive fitting rules in hearing aid users

PURPOSE

The primary aim of this research study is to assess whether differences exist in the application of the NAL-NL2 and DSL v.5 prescription formulas in terms of speech-in-noise intelligibility.

METHODS

Data from 43 patients, were retrospectively evaluated and analyzed. Inclusion criteria were patients with bilateral conductive, sensorineural, or mixed hearing loss, already using hearing aids for at least 1 year, and aged 18 years or older. Patients were categorized into two groups based on the prescriptive method employed by the hearing aid: NAL-NL2 or DSL v.5. Pure tone audiometry, speech audiometry, free field pure tone and speech audiometry with the hearing aid, and Matrix sentence test were performed. The Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire was used to assess the personal audiological benefit provided by the hearing aid.

RESULTS

No statistically significant differences were found comparing the free-field pure tone average (FF PTA) and the free-field Word Recognition Score (FF WRS). Comparing the Speech Reception Threshold (SRT) parameter of patients with NAL-NL2 vs DSL v.5, no statistically significant difference was found, thus highlighting a condition of comparability between the two prescription methods in terms of speech-in-noise intelligibility. Comparing the results of the APHAB questionnaire, no statistically significant differences were evident for all subscales and overall benefit. When conducting a comparison between male and female patients using the NAL-NL2 method, no differences were observed in SRT values, however, the APHAB questionnaire revealed a difference in the AV subscale score for the same subjects.

CONCLUSION

Our analysis revealed no statistically significant differences in speech-in-noise intelligibility, as measured by the SRT values from the Matrix Sentence Test, when comparing the two prescriptive methods. This compelling result reinforces the notion that, functionally, both methods are comparably effective in enhancing speech intelligibility in real-world, noisy environments. However, it is crucial to underscore that the absence of differences does not diminish the importance of considering individual patient needs and preferences in the selection of a prescriptive method.

Pediatric normative data for a novel and fast speech perception test in noise

OBJECTIVES

Communicating in noisy settings can be difficult due to interference and environmental noise, which can impact intelligibility for those with hearing impairments and those with normal hearing threshold. Speech intelligibility is commonly assessed in audiology through speech audiometry in quiet environments. Nevertheless, this test may not effectively assess hearing challenges in noisy environments, as total silence is rare in daily activities. A recently patented method, known as the SRT50 FAST, has been developed for conducting speech audiometry in noise. This new method enables the acceleration and simplification of free field speech audiometry tests involving competition noise. This study aims to establish normative scores and standardize the SRT50 FAST method as a test for evaluating speech perception in noise in pediatric patients.

METHODS

The study included 30 participants with normal hearing, consisting of 11 females and 19 males, ranging in age from 6 to 11 years. A series of speech audiometry tests were conducted to determine the speech reception threshold 50% (SRT50) in competing conditions. This included testing both the fast mode (SRT50 FAST) currently being studied and the traditional method (SRT50 CLASSIC). The SRT50, or Signal to Noise Ratio (SNR) at which 50% of speech recognition occurred, was investigated for both methods.

RESULTS

The mean SRT50 FAST test score was -2.69 (SD = 3.15). The dataset exhibited a normal distribution with values ranging from 3.60 to -8.60. Since the scores are expressed in SRT, higher scores indicate poorer performance. We have established a threshold of 3.60 as the upper limit of the normal range, therefore, patients with scores above this threshold are considered to have abnormal results.

CONCLUSIONS

This study aimed to establish normative data for the evaluation of free field speech in noise recognition using the SRT50 FAST method in the pediatric population. This method accurately investigates the necessary signal-to-noise ratio for achieving 50% recognition scores with bisyllabic words in a quick manner. The ultimate objective is to employ this test to identify the optimal configuration of hearing rehabilitation devices, particularly for pediatric patients with hearing aids and/or cochlear implants. Additionally, it can be used to assess pediatric patients with unilateral hearing loss.

Homogeneity of the 18 QuickSIN™ Lists

The purpose of this study was to determine the list equivalency of the 18 QuickSIN™ (Quick Speech in Noise test) lists. Individuals with normal hearing (n = 24) and with sensorineural hearing loss (n = 72) were studied. Mean recognition performances on the 18 lists by the listeners with normal hearing were 2.8 to 4.3 dB SNR (signal-to-noise ratio), whereas the range was 10.0 to 14.3 dB SNR for the listeners with hearing loss. The psychometric functions for each list showed high performance variability across lists for listeners with hearing loss but not for listeners with normal hearing. For listeners with hearing loss, Lists 4, 5, 13, and 16 fell outside of the critical difference. The data from this study suggest nine lists that provide homogenous results for listeners with and without hearing loss. Finally, there was an 8.7 dB difference in performances between the two groups indicating a more favorable signal-to-noise ratio required by the listeners with hearing loss to obtain equal performance.

Effects of Adult Aging and Hearing Loss on Comprehension of Rapid Speech Varying in Syntactic Complexity

Comprehension of spoken language by older adults depends not only on effects of hearing acuity and age-related cognitive change but also on characteristics of the message, such as syntactic complexity and presentation rate. When younger and older adults with clinically normal hearing and with mild-to-moderate hearing loss were tested on comprehension of short spoken sentences that varied in syntactic complexity, minimal effects of age and hearing were seen in comprehension of syntactically simpler sentences, even at rapid speech rates. By contrast, both age and hearing loss were associated with poorer comprehension for more syntactically complex sentences, and these differences were further exacerbated by increases in speech rate. These findings illustrate a dynamic interaction between age, hearing acuity, and characteristics of the spoken message on speech comprehension.

Assessment of Hidden Hearing Loss in Normal Hearing Individuals with and Without Tinnitus

OBJECTIVES

To evaluate the functions of cochlear structures and the distal part of auditory nerve as well as dead regions within the cochlea in individuals with normal hearing with or without tinnitus by using electrophysiological tests.

MATERIALS AND METHODS

Nine individuals (ages: 21-59 years) with normal hearing with tinnitus were included in the study group. Thirteen individuals (ages: 25-60 years) with normal hearing without tinnitus were included in the control group. Immitancemetric examination, pure-tone audiometry (125Hz-16kHz), speech audiometry in quiet and noise environments, transient evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs), threshold equalizing noise (TEN test (500Hz-4kHz), and ECochG tests, Beck Depression Questionnaire, Tinnitus Handicap Questionnaire, and Visual Analog Scale were performed.

RESULTS

In the study group, three patients were found to have a minimal depression and six were found to have a mild depression. In pure-tone audiometry, the threshold (6-16 kHz) in the study group was significantly higher than that of the control group at all frequencies. In the study group, lower performance scores were obtained in speech discrimination in noise in both ears. In the control group, no dead region was detected in the TEN test whereas 75% of subjects in the study group had dead regions. DPOAE and TEOAE responses between study and control group subjects were not different. In the ECochG test, subjects in the study group showed an increase in the summating potential/action potential (SP/AP) ratio in both ears.

CONCLUSION

Determination of the SP/AP ratio in patients with tinnitus may be useful in diagnosing hidden hearing loss. Detection of dead regions in 75% of patients in the TEN test may indicate that inner hair cells may be responsible for tinnitus.

Evaluation of a sentence test in noise in children with hearing impairment

INTRODUCTION

School-aged children with hearing impairment (HI) listen and learn in noisy environments. On-going monitoring of speech understanding in noise is essential to adjust clinical interventions accordingly.

METHODS

The aim of this study was to assess Dantale II in a paediatric population. The secondary aims were identification of differences and similarities between groups of children with HI and normal hearing and between different hearing technologies; investigation of possible associations between Dantale II and verbal working memory. This was a longitudinal, prospective study comparing groups of children (n = 70) using the Dantale II with five-word sentences and verbal working memory with the Clinical Evaluation of Language Functioning-4.

RESULTS

Dantale II seems clinically feasible from the age of six years. Children with NH outperformed children with HI both on completion of the tests and dB signal-to-noise ratio (SNR) scores. Children with hearing aids outperformed children with cochlear implants on dB SNR scores. A significant and moderately strong association between speech understanding in noise and verbal working memory was identified.

CONCLUSIONS

Our study produced knowledge about a new generation of children with HI, who showed potentials not previously described. Future research on cognitive development of paediatric populations with HI is essential, as knowledge from adult populations cannot be transferred directly to paediatric populations.

FUNDING

The project received funding from the Innovation Foundation, the Oticon Foundation, Decibel and The Capital Region of Denmark.

TRIAL REGISTRATION

not relevant.

Systematic Audiological Assessment of Auditory Functioning in Patients With Parkinson's Disease

Purpose Alterations in primary auditory functioning have been reported in patients with Parkinson's disease (PD). Despite the current findings, the pathophysiological mechanisms underlying these alterations remain unclear, and the effect of dopaminergic medication on auditory functioning in PD has been explored insufficiently. Therefore, this study aimed to systematically investigate primary auditory functioning in patients with PD by using both subjective and objective audiological measurements. Method In this case-control study, 25 patients with PD and 25 age-, gender-, and education-matched healthy controls underwent an audiological test battery consisting of tonal audiometry, short increment sensitivity index, otoacoustic emissions (OAEs), and speech audiometry. Patients with PD were tested in the on- and off-medication states. Results Increased OAE amplitudes were found when patients with PD were tested without dopaminergic medication. In addition, speech audiometry in silence and multitalker babble noise demonstrated higher phoneme scores for patients with PD in the off-medication condition. The results showed no differences in auditory functioning between patients with PD in the on-medication condition and healthy controls. No effect of disease stage or motor score was evident. Conclusions This study provides evidence for a top-down involvement in auditory processing in PD at both central and peripheral levels. Most important, the increase in OAE amplitude in the off-medication condition in PD is hypothesized to be linked to a dysfunction of the olivocochlear efferent system, which is known to have an inhibitory effect on outer hair cell functioning. Future studies may clarify whether OAEs may facilitate an early diagnosis of PD.

Measuring open-set, word recognition in school-aged children: Corpus of monosyllabic target words and speech maskers

A corpus of stimuli has been collected to support the use of common materials across research laboratories to examine school-aged children's word recognition in speech maskers. The corpus includes (1) 773 monosyllabic words that are known to be in the lexicon of 5- and 6-year-olds and (2) seven masker passages that are based on a first-grade child's writing samples. Materials were recorded by a total of 13 talkers (8 women; 5 men). All talkers recorded two masker passages; 3 talkers (2 women; 1 man) also recorded the target words. The annotated corpus is freely available online for research purposes.

Typical vs. atypical: Combining auditory Gestalt perception and acoustic analysis of early vocalisations in Rett syndrome

BACKGROUND

Early speech-language development of individuals with Rett syndrome (RTT) has been repeatedly characterised by a co-occurrence of apparently typical and atypical vocalisations.

AIMS

To describe specific features of this intermittent character of typical versus atypical early RTT-associated vocalisations by combining auditory Gestalt perception and acoustic vocalisation analysis.

METHODS AND PROCEDURES

We extracted N = 363 (pre-)linguistic vocalisations from home video recordings of an infant later diagnosed with RTT. In a listening experiment, all vocalisations were assessed for (a)typicality by five experts on early human development. Listeners' auditory concepts of (a)typicality were investigated in context of a comprehensive set of acoustic time-, spectral- and/or energy-related higher-order features extracted from the vocalisations.

OUTCOMES AND RESULTS

More than half of the vocalisations were rated as 'atypical' by at least one listener. Atypicality was mainly related to the auditory attribute 'timbre', and to prosodic, spectral, and voice quality features in the acoustic domain.

CONCLUSIONS AND IMPLICATIONS

Knowledge gained in our study shall contribute to the generation of an objective model of early vocalisation atypicality. Such a model might be used for increasing caregivers' and healthcare professionals' sensitivity to identify atypical vocalisation patterns, or even for a probabilistic approach to automatically detect RTT based on early vocalisations.

The Self-Assessed Békesy Procedure: Validation of a Method to Measure Intelligibility of Connected Discourse

In clinical practice and research, speech intelligibility is generally measured by instructing the participant to recall sentences. Although this is a reliable and highly repeatable measure, it cannot be used to measure intelligibility of connected discourse. Therefore, we developed a new method, the self-assessed Békesy procedure, which is an adaptive procedure that uses intelligibility ratings to converge to a person's speech reception threshold. In this study, we describe the new procedure and the validation in young, normal-hearing listeners. First, we compared the results on the self-assessed Békesy procedure to a recall procedure for standardized sentences. Next, we evaluated the inter- and intrasubject variability of our procedure. Furthermore, we compared the thresholds for sentences in three masker types between the self-assessed Békesy and a recall procedure to verify if these procedures resulted in similar conclusions. Finally, we compared the thresholds for two types of sentences and commercial recordings of stories. In general, the self-assessed Békesy procedure is shown to be a valid and reliable procedure as similar thresholds (difference < 1 dB) and test-retest reliability (< 1.5 dB) were observed compared with standard speech audiometry tests. In addition, the time efficiency and similar differences between maskers to a recall procedure support the potential of this procedure to be implemented in research. Finally, significant differences between the thresholds of sentences and connected discourse materials were found, indicating the importance of controlling for differences in intelligibility when presenting these materials at the same signal-to-noise ratios or when comparing studies.

Vibro-Tactile Enhancement of Speech Intelligibility in Multi-talker Noise for Simulated Cochlear Implant Listening

Many cochlear implant (CI) users achieve excellent speech understanding in acoustically quiet conditions but most perform poorly in the presence of background noise. An important contributor to this poor speech-in-noise performance is the limited transmission of low-frequency sound information through CIs. Recent work has suggested that tactile presentation of this low-frequency sound information could be used to improve speech-in-noise performance for CI users. Building on this work, we investigated whether vibro-tactile stimulation can improve speech intelligibility in multi-talker noise. The signal used for tactile stimulation was derived from the speech-in-noise using a computationally inexpensive algorithm. Eight normal-hearing participants listened to CI simulated speech-in-noise both with and without concurrent tactile stimulation of their fingertip. Participants' speech recognition performance was assessed before and after a training regime, which took place over 3 consecutive days and totaled around 30 min of exposure to CI-simulated speech-in-noise with concurrent tactile stimulation. Tactile stimulation was found to improve the intelligibility of speech in multi-talker noise, and this improvement was found to increase in size after training. Presentation of such tactile stimulation could be achieved by a compact, portable device and offer an inexpensive and noninvasive means for improving speech-in-noise performance in CI users.

[Speech audiometry, speech perception and cognitive functions. German version]

Examination of cognitive functions in the framework of speech perception has recently gained increasing scientific and clinical interest. Especially against the background of age-related hearing impairment and cognitive decline potential new perspectives in terms of better individualisation of auditory diagnosis and rehabilitation might arise. This review addresses the relationships of speech audiometry, speech perception and cognitive functions. It presents models of speech perception, discusses associations of neuropsychological with audiometric outcomes and shows recent efforts to consider cognitive functions with speech audiometry.

The role of short-time intensity and envelope power for speech intelligibility and psychoacoustic masking

The generalized power spectrum model [GPSM; Biberger and Ewert (2016). J. Acoust. Soc. Am. 140, 1023-1038], combining the "classical" concept of the power-spectrum model (PSM) and the envelope power spectrum-model (EPSM), was demonstrated to account for several psychoacoustic and speech intelligibility (SI) experiments. The PSM path of the model uses long-time power signal-to-noise ratios (SNRs), while the EPSM path uses short-time envelope power SNRs. A systematic comparison of existing SI models for several spectro-temporal manipulations of speech maskers and gender combinations of target and masker speakers [Schubotz et al. (2016). J. Acoust. Soc. Am. 140, 524-540] showed the importance of short-time power features. Conversely, Jørgensen et al. [(2013). J. Acoust. Soc. Am. 134, 436-446] demonstrated a higher predictive power of short-time envelope power SNRs than power SNRs using reverberation and spectral subtraction. Here the GPSM was extended to utilize short-time power SNRs and was shown to account for all psychoacoustic and SI data of the three mentioned studies. The best processing strategy was to exclusively use either power or envelope-power SNRs, depending on the experimental task. By analyzing both domains, the suggested model might provide a useful tool for clarifying the contribution of amplitude modulation masking and energetic masking.

Speech based transmission index for all: An intelligibility metric for variable hearing ability

A method to measure the speech intelligibility in public address systems for normal hearing and hearing impaired persons is presented. The proposed metric is an extension of the speech based Speech Transmission Index to account for accurate perceptual masking and variable hearing ability: The sound excitation pattern generated at the ear is accurately computed using an auditory filter model, and its shapes depend on frequency, sound level, and hearing impairment. This extension yields a better prediction of the intensity of auditory masking which is used to rectify the modulation transfer function and thus to objectively assess the speech intelligibility experienced by hearing impaired as well as by normal hearing persons in public spaces. The proposed metric was developed within the framework of the European Active and Assisted Living research program, and was labeled "SB-STI for All." Extensive subjective in-Lab and in vivo tests have been conducted and the proposed metric proved to have a good correlation with subjective intelligibility scores.

Assessing the efficacy of hearing-aid amplification using a phoneme test

Consonant-vowel (CV) perception experiments provide valuable insights into how humans process speech. Here, two CV identification experiments were conducted in a group of hearing-impaired (HI) listeners, using 14 consonants followed by the vowel /ɑ/. The CVs were presented in quiet and with added speech-shaped noise at signal-to-noise ratios of 0, 6, and 12 dB. The HI listeners were provided with two different amplification schemes for the CVs. In the first experiment, a frequency-independent amplification (flat-gain) was provided and the CVs were presented at the most-comfortable loudness level. In the second experiment, a frequency-dependent prescriptive gain was provided. The CV identification results showed that, while the average recognition error score obtained with the frequency-dependent amplification was lower than that obtained with the flat-gain, the main confusions made by the listeners on a token basis remained the same in a majority of the cases. An entropy measure and an angular distance measure were proposed to assess the highly individual effects of the frequency-dependent gain on the consonant confusions in the HI listeners. The results suggest that the proposed measures, in combination with a well-controlled phoneme speech test, may be used to assess the impact of hearing-aid signal processing on speech intelligibility.

Release from masking for small spatial separations: Effects of age and hearing loss

Spatially separating target and masking speech can result in substantial spatial release from masking (SRM) for normal-hearing listeners. In this study, SRM was examined at eight spatial configurations of azimuth angle: maskers co-located with the target (0°) or symmetrically separated by 2°, 4°, 6°, 8°, 10°, 15°, or 30°. Results revealed that different listening groups (young normal-hearing, older normal-hearing, and older hearing-impaired) required different minimum amounts of spatial separation between target and maskers to achieve SRM. The results also indicated that aging was the contributing factor predicting SRM at smaller separations, whereas hearing loss was the contributing factor at larger separations.

Reference-Free Assessment of Speech Intelligibility Using Bispectrum of an Auditory Neurogram

Sensorineural hearing loss occurs due to damage to the inner and outer hair cells of the peripheral auditory system. Hearing loss can cause decreases in audibility, dynamic range, frequency and temporal resolution of the auditory system, and all of these effects are known to affect speech intelligibility. In this study, a new reference-free speech intelligibility metric is proposed using 2-D neurograms constructed from the output of a computational model of the auditory periphery. The responses of the auditory-nerve fibers with a wide range of characteristic frequencies were simulated to construct neurograms. The features of the neurograms were extracted using third-order statistics referred to as bispectrum. The phase coupling of neurogram bispectrum provides a unique insight for the presence (or deficit) of supra-threshold nonlinearities beyond audibility for listeners with normal hearing (or hearing loss). The speech intelligibility scores predicted by the proposed method were compared to the behavioral scores for listeners with normal hearing and hearing loss both in quiet and under noisy background conditions. The results were also compared to the performance of some existing methods. The predicted results showed a good fit with a small error suggesting that the subjective scores can be estimated reliably using the proposed neural-response-based metric. The proposed metric also had a wide dynamic range, and the predicted scores were well-separated as a function of hearing loss. The proposed metric successfully captures the effects of hearing loss and supra-threshold nonlinearities on speech intelligibility. This metric could be applied to evaluate the performance of various speech-processing algorithms designed for hearing aids and cochlear implants.

Health-related quality of life and mental distress in patients with partial deafness: preliminary findings

The aim of the study was to evaluate mental distress and health-related quality of life in patients with bilateral partial deafness (high-frequency sensorineural hearing loss) before cochlear implantation, with respect to their audiological performance and time of onset of the hearing impairment. Thirty-one patients and 31 normal-hearing individuals were administered the Beck Depression Inventory (BDI), the State-Trait-Anxiety-Inventory (STAI) and the World Health Organization Quality of Life-BREF questionnaire (WHOQOL-BREF). Patients also completed the Nijmegen-Cochlear-Implant-Questionnaire (NCIQ), a tool for evaluation of quality of life related to hearing loss. Patients revealed increased depressive and anxiety symptoms, as well as decreased health-related quality of life (psychological health, physical health), in comparison with their healthy counterparts (t tests, p < 0.05). Furthermore, a General Linear Model demonstrated in patients with a prelingual onset of hearing loss enhanced self-evaluated social interactions and activity (NCIQ), when their outcomes were contrasted with those obtained in individuals with postlingual partial deafness (p < 0.05). The study failed to show any effect of collateral tinnitus. Patients not using hearing aids had better audiological performance and, therefore, better sound perception and speech production, as measured with NCIQ. There was no effect of hearing aid use with respect to mental distress. Additional statistically significant correlations seen in patients included those between a steeper slope hearing loss configuration (averaged pure-tone thresholds at 1 and 2 kHz with subtracted threshold at 0.5 kHz) and better audiometric speech detection, between audiometric thresholds and the subjectively rated sound perception (NCIQ), as well as left-ear audiometric word recognition scores and the subjectively perceived ability to recognize advanced sounds (NCIQ). In addition, a longer duration of postlingual deafness, as well as a younger age at the onset were both related to worse speech detection thresholds. The results of the study provide evidence that successful rehabilitation in patients with partial deafness might have to go beyond the standard speech therapy. Enhancement of the regular diagnostic assessment with additional psychological tools is highly recommended. Further investigation is required as to the role of functional residual hearing, hearing aid use and tinnitus, in relation to future outcomes of cochlear implantation.

[The use of speech audiometry in the practice of the geriatric center]

The aim of the study was to evaluate a new test of speech audiometry while examining aged patients. 32 aged listeners from 60 to 88 years old were examined: 20 hearing aid (HA) users and 12 patients with normal hearing thresholds and mild cognitive impairment according to the results of the mini-mental state examination (MMSE). The speech audiometry consisted of the traditional polysyllabic words discrimination test and a new speech test with motor responses (Verbal Tasks and Motor Responses - VTMR); in both tests the signal was presented in background noise (polyphony) in free field. All listeners performed the VTMR test significantly better than the polysyllabic words discrimination test. In the group of hearing impaired patients the mean result in VTMR test was 73,2±29,2 % without HA and 88,6±20,5 % with it, in traditional test - 34,8±20,9 % without HA and 56±18,4 % with it. All patients of the group with normal hearing and mild cognitive impairment performed the VTMR test with 100 % result, their speech discrimination score in traditional test was 88±12 %. In the practice of the geriatric center the use of both the traditional speech audiometry and the new speech test with motor responses seems to be reasonable, that allows examining the auditory function in patients with significant deterioration of speech intelligibility or cognitive impairment.

Validation of a simple response-time measure of listening effort

This study compares two response-time measures of listening effort that can be combined with a clinical speech test for a more comprehensive evaluation of total listening experience; verbal response times to auditory stimuli (RT(aud)) and response times to a visual task (RTs(vis)) in a dual-task paradigm. The listening task was presented in five masker conditions; no noise, and two types of noise at two fixed intelligibility levels. Both the RTs(aud) and RTs(vis) showed effects of noise. However, only RTs(aud) showed an effect of intelligibility. Because of its simplicity in implementation, RTs(aud) may be a useful effort measure for clinical applications.

Acquired auditory neuropathy spectrum disorder after an attack of chikungunya: case study

Auditory neuropathy spectrum disorder (ANSD) is a retrocochlear disorder in which the cochlear functioning is normal but the transmission in the auditory neural pathway is affected. The present study reports of a 14-year-old teenager with acquired ANSD after an attack of chikungunya. He reported symptoms of difficulty in understanding speech, tinnitus and vertigo when exposed to loud sounds. The audiological characteristics suggested auditory neuropathy spectrum disorder with raising audiogram configuration. The results of tinnitus evaluation showed low-pitched tinnitus and it was persistent causing significant handicap to him based on self report tinnitus handicap questionnaire results. The results of depression, anxiety and stress scale also suggested symptoms of mild depression and anxiety. Chikungunya virus is suspected to be neurotropic in nature which can damage auditory nerve cells and may have caused ANSD. The result also shows presence of tullio's phenomenon and absence of cervical vestibular evoked myogenic potentials suggesting damage to the vestibular neuronal system. The possible pathophysiology of chikungunya virus causing ANSD and vestibular symptoms needs to be explored further in future studies.

A corpus of noise-induced word misperceptions for Spanish

Word misperceptions are valuable in designing and evaluating detailed computational models of speech perception, especially when a number of listeners agree on the misperceived word. The current paper describes the elicitation of a corpus of Spanish word misperceptions induced by different types of noise. Stimuli were presented using an adaptive procedure designed to promote the rapid discovery of misperceptions. The final corpus contains 3235 misperceptions along with speech and masker waveforms, permitting further experimental and modeling studies into the origin of each misperception. The corpus is available online as an open resource.

Effects of envelope bandwidth on importance functions for cochlear implant simulations

Frequency-importance functions (FIFs) quantify intelligibility contributions of spectral regions of speech. In previous work, FIFs were considered as instruments for characterizing intelligibility contributions of individual cochlear implant electrode channels. Comparisons of FIFs for natural speech and vocoder-simulated implant processed speech showed that vocoding shifted peak importance regions downward in frequency by 0.5 octaves. These shifts were attributed to voicing cue changes, and may reflect increased reliance on low-frequency information (apart from periodicity cues) for correct voicing perception. The purpose of this study was to determine whether increasing channel envelope bandwidth would reverse these shifts by improving access to voicing and pitch cues. Importance functions were measured for 48 subjects with normal hearing, who listened to vowel-consonant-vowel tokens either as recorded or as output from five different vocoders that simulated implant processing. Envelopes were constructed using filters that either included or excluded pitch information. Results indicate that vocoding-based shifts are only partially counteracted by including pitch information; moreover, a substantial baseline shift is present even for vocoders with high spectral resolution. The results also suggest that vocoded speech intelligibility is most sensitive to a loss of spectral resolution in high-importance regions, a finding with possible implications for cochlear implant electrode mapping.

Spectral and temporal resolutions of information-bearing acoustic changes for understanding vocoded sentences

Short-time spectral changes in the speech signal are important for understanding noise-vocoded sentences. These information-bearing acoustic changes, measured using cochlea-scaled entropy in cochlear implant simulations [CSECI; Stilp et al. (2013). J. Acoust. Soc. Am. 133(2), EL136-EL141; Stilp (2014). J. Acoust. Soc. Am. 135(3), 1518-1529], may offer better understanding of speech perception by cochlear implant (CI) users. However, perceptual importance of CSECI for normal-hearing listeners was tested at only one spectral resolution and one temporal resolution, limiting generalizability of results to CI users. Here, experiments investigated the importance of these informational changes for understanding noise-vocoded sentences at different spectral resolutions (4-24 spectral channels; Experiment 1), temporal resolutions (4-64 Hz cutoff for low-pass filters that extracted amplitude envelopes; Experiment 2), or when both parameters varied (6-12 channels, 8-32 Hz; Experiment 3). Sentence intelligibility was reduced more by replacing high-CSECI intervals with noise than replacing low-CSECI intervals, but only when sentences had sufficient spectral and/or temporal resolution. High-CSECI intervals were more important for speech understanding as spectral resolution worsened and temporal resolution improved. Trade-offs between CSECI and intermediate spectral and temporal resolutions were minimal. These results suggest that signal processing strategies that emphasize information-bearing acoustic changes in speech may improve speech perception for CI users.

Release from informational masking in a monaural competing-speech task with vocoded copies of the maskers presented contralaterally

Single-sided deafness prevents access to the binaural cues that help normal-hearing listeners extract target speech from competing voices. Little is known about how listeners with one normal-hearing ear might benefit from access to severely degraded audio signals that preserve only envelope information in the second ear. This study investigated whether vocoded masker-envelope information presented to one ear could improve performance for normal-hearing listeners in a multi-talker speech-identification task presented to the other ear. Target speech and speech or non-speech maskers were presented unprocessed to the left ear. The right ear received no signal, or either an unprocessed or eight-channel noise-vocoded copy of the maskers. Presenting the vocoded maskers contralaterally yielded significant masking release from same-gender speech maskers, albeit less than in the unprocessed case, but not from opposite-gender speech, stationary-noise, or modulated-noise maskers. Unmasking also occurred with as few as two vocoder channels and when an attenuated copy of the target signal was added to the maskers before vocoding. These data show that delivering masker-envelope information contralaterally generates masking release in situations where target-masker similarity impedes monaural speech-identification performance. By delivering speech-envelope information to a deaf ear, cochlear implants for single-sided deafness have the potential to produce a similar effect.

Speech Intelligibility of the Callsign Acquisition Test in a Quiet Environment

This paper reports on preliminary experiments aimed at standardizing speech intelligibility of military Callsign Acquisition Test (CAT) using average power levels of callsign items measured by the Root Mean Square (RMS) and maximum power levels of callsign items (Peak). The results obtained indicate that at a minimum sound pressure level (SPL) of 10.57 dBHL, the CAT tests were more difficult than NU-6 (Northwestern University, Auditory Test No. 6) and CID-W22 (Central Institute for the Deaf, Test W-22). At the maximum SPL values, the CAT tests reveal more intelligibility than NU-6 and CID-W22. The CAT-Peak test attained 95% intelligibility as NU-6 at 27.5 dBHL, and with CID-W22, 92.4% intelligibility at 27 dBHL. The CAT-RMS achieved 90% intelligibility when compared with NU-6, and 87% intelligibility score when compared with CID-W22; all at 24 dBHL.

Development of a test battery for evaluating speech perception in complex listening environments

In the real world, spoken communication occurs in complex environments that involve audiovisual speech cues, spatially separated sound sources, reverberant listening spaces, and other complicating factors that influence speech understanding. However, most clinical tools for assessing speech perception are based on simplified listening environments that do not reflect the complexities of real-world listening. In this study, speech materials from the QuickSIN speech-in-noise test by Killion, Niquette, Gudmundsen, Revit, and Banerjee [J. Acoust. Soc. Am. 116, 2395-2405 (2004)] were modified to simulate eight listening conditions spanning the range of auditory environments listeners encounter in everyday life. The standard QuickSIN test method was used to estimate 50% speech reception thresholds (SRT50) in each condition. A method of adjustment procedure was also used to obtain subjective estimates of the lowest signal-to-noise ratio (SNR) where the listeners were able to understand 100% of the speech (SRT100) and the highest SNR where they could detect the speech but could not understand any of the words (SRT0). The results show that the modified materials maintained most of the efficiency of the QuickSIN test procedure while capturing performance differences across listening conditions comparable to those reported in previous studies that have examined the effects of audiovisual cues, binaural cues, room reverberation, and time compression on the intelligibility of speech.

A method for measuring the intelligibility of uninterrupted, continuous speech

Speech-in-noise tests commonly use short, discrete sentences as representative samples of everyday speech. These tests cannot, however, fully represent the added demands of understanding ongoing, linguistically complex speech. Using a new monitoring method to measure the intelligibility of continuous speech and a standard trial-by-trial, speech-in-noise test the effects of target duration and linguistic complexity were examined. For a group of older hearing-impaired listeners, significantly higher speech reception thresholds were found for continuous, complex speech targets than for syntactically simple sentences. The results highlight the need to sample speech intelligibility in a variety of everyday speech-in-noise scenarios.

Effects of noise suppression on intelligibility. II: An attempt to validate physical metrics

Using the data presented in the accompanying paper [Hilkhuysen et al., J. Acoust. Soc. Am. 131, 531-539 (2012)], the ability of six metrics to predict intelligibility of speech in noise before and after noise suppression was studied. The metrics considered were the Speech Intelligibility Index (SII), the fractional Articulation Index (fAI), the coherence intelligibility index based on the mid-levels in speech (CSIImid), an extension of the Normalized Coherence Metric (NCM+), a part of the speech-based envelope power model (pre-sEPSM), and the Short Term Objective Intelligibility measure (STOI). Three of the measures, SII, CSIImid, and NCM+, overpredicted intelligibility after noise reduction, whereas fAI underpredicted these intelligibilities. The pre-sEPSM metric worked well for speech in babble but failed with car noise. STOI gave the best predictions, but overall the size of intelligibility prediction errors were greater than the change in intelligibility caused by noise suppression. Suggestions for improvements of the metrics are discussed.

A Danish open-set speech corpus for competing-speech studies

Studies investigating speech-on-speech masking effects commonly use closed-set speech materials such as the coordinate response measure [Bolia et al. (2000). J. Acoust. Soc. Am. 107, 1065-1066]. However, these studies typically result in very low (i.e., negative) speech recognition thresholds (SRTs) when the competing speech signals are spatially separated. To achieve higher SRTs that correspond more closely to natural communication situations, an open-set, low-context, multi-talker speech corpus was developed. Three sets of 268 unique Danish sentences were created, and each set was recorded with one of three professional female talkers. The intelligibility of each sentence in the presence of speech-shaped noise was measured. For each talker, 200 approximately equally intelligible sentences were then selected and systematically distributed into 10 test lists. Test list homogeneity was assessed in a setup with a frontal target sentence and two concurrent masker sentences at ±50° azimuth. For a group of 16 normal-hearing listeners and a group of 15 elderly (linearly aided) hearing-impaired listeners, overall SRTs of, respectively, +1.3 dB and +6.3 dB target-to-masker ratio were obtained. The new corpus was found to be very sensitive to inter-individual differences and produced consistent results across test lists. The corpus is publicly available.

Development and evaluation of a linguistically and audiologically controlled sentence intelligibility test

To allow for a systematic variation of linguistic complexity of sentences while acoustically controlling for intelligibility of sentence fragments, a German corpus, Oldenburg linguistically and audiologically controlled sentences (OLACS), was designed, implemented, and evaluated. Sentences were controlled for plausibility with a questionnaire survey. Verification of the speech material was performed in three listening conditions (quiet, stationary, and fluctuating noise) by collecting speech reception thresholds (SRTs) and response latencies as well as individual cognitive measures for 20 young listeners with normal hearing. Consistent differences in response latencies across sentence types verified the effect of linguistic complexity on processing speed. The addition of noise decreased response latencies, giving evidence for different response strategies for measurements in noise. Linguistic complexity had a significant effect on SRT. In fluctuating noise, this effect was more pronounced, indicating that fluctuating noise correlates with stronger cognitive contributions. SRTs in quiet correlated with hearing thresholds, whereas cognitive measures explained up to 40% of the variance in SRTs in noise. In conclusion, OLACS appears to be a suitable tool for assessing the interaction between aspects of speech understanding (including cognitive processing) and speech intelligibility in German.

Psychometric properties associated with perceived vocal roughness using a matching task

A psychophysical matching paradigm has been used to better quantify voice quality under laboratory conditions. The goals of this study were to establish which of two candidate comparison stimuli would best ensure that the range of perceived vocal roughness could be adequately bracketed using a matching task and to provide a general solution to the problem of estimating vocal roughness. Psychometric functions for roughness matching indicated that a speech-like sawtooth-plus-noise complex (20 dB signal-to-noise ratio) amplitude modulated by a sinusoidal function raised to the 4th power yielded a comparison stimulus with a perceptual dynamic range well suited for roughness matching.

Contralateral hearing aid use in cochlear implanted patients: multicenter study of bimodal benefit

CONCLUSION

The use of a hearing aid (HA) in combination with a cochlear implant (CI) significantly improved performance for speech perception in quiet, in noise, and for localization compared with monaural conditions. No significant differences in functional performance were observed following optimization of HA fitting.

OBJECTIVES

To evaluate the binaural benefits derived from using a contralateral HA in conjunction with a CI in subjects with significant functional hearing in the nonimplanted ear and the effects of HA fitting optimization.

METHODS

Fifteen adult CI users, intra-subject controls, were enrolled in a prospective repeated-measure multicenter study. Evaluation of performance for speech understanding, localization, and subjective impressions was conducted before and following HA fitting optimization for CI alone, HA alone, and CI + HA.

RESULTS

For speech testing in quiet, bimodal scores were significantly better than for HA alone and CI alone conditions (p < 0.01). For speech and noise (S0N0) at 0° azimuth the scores were significantly better in the bimodal condition than for CI alone (p = 0.01), indicating binaural summation. When noise was presented to the HA side (S0NHA) bimodal scores were significantly better than for CI alone (p < 0.01 and p < 0.05, respectively), suggesting a significant binaural squelch effect. Sound localization ability was significantly improved in the bimodal condition compared with the CI alone condition (p = 0.002).

Assessment of the peripheral hearing system of sport divers

OBJECTIVE

To investigate the effect of regular scuba diving on the hearing thresholds of sport divers who have no history of noise exposure or ear-related accidents. Comprehensive topographic examination of the peripheral hearing system of sport divers.

DESIGN

Cross-sectional study.

SETTINGS

General sport diving community.

PARTICIPANTS

81 sport divers with a mean of 300 dives each were compared to a control group of 81 non-divers.

MAIN OUTCOME MEASURE

Participants were classified into three age groups. Examination included microscopic otoscopy, tympanometry, pure-tone audiometry (PTA) including air and bone conduction, speech audiometry and otoacoustic emissions (OAE).

RESULTS

PTA suggested significant differences of the hearing thresholds at several frequencies between sport divers and non-divers in all age groups, although a Bonferroni correction for multiple testing was applied. Interestingly, the results were contradictory. Divers obtained better hearing results in air conduction, whereas non-divers showed better results in bone conduction. Speech audiometry and OAE did not reveal significant differences.

CONCLUSION

There are no published studies of the peripheral cochlear system of divers that have used a combination of PTA, speech audiometry and OAE. All studies suggesting hearing impairment in divers were based on PTA and might have been influenced by a lack of accuracy of PTA. Our results suggest that diving does not adversely affect the hearing system of sport divers. A thorough test battery of audiological methods implying PTA, speech audiometry and OAE may contribute to offer more reliable results to answer the question of whether commercial or military divers are at higher risk for hearing detoriation.

Automatic estimation of voice onset time for word-initial stops by applying random forest to onset detection

The voice onset time (VOT) of a stop consonant is the interval between its burst onset and voicing onset. Among a variety of research topics on VOT, one that has been studied for years is how VOTs are efficiently measured. Manual annotation is a feasible way, but it becomes a time-consuming task when the corpus size is large. This paper proposes an automatic VOT estimation method based on an onset detection algorithm. At first, a forced alignment is applied to identify the locations of stop consonants. Then a random forest based onset detector searches each stop segment for its burst and voicing onsets to estimate a VOT. The proposed onset detection can detect the onsets in an efficient and accurate manner with only a small amount of training data. The evaluation data extracted from the TIMIT corpus were 2344 words with a word-initial stop. The experimental results showed that 83.4% of the estimations deviate less than 10 ms from their manually labeled values, and 96.5% of the estimations deviate by less than 20 ms. Some factors that influence the proposed estimation method, such as place of articulation, voicing of a stop consonant, and quality of succeeding vowel, were also investigated.

[Modern aspects of diagnosis of presbycusis and its treatment in elderly patients]

This study was designed to evaluate the efficacy of tanakan used to treat tympanophonia in elderly women. The entire spectrum of modern audiological technique was employed to examine the patients. It was shown that tanakan therapy decreases intensity of typmanytis and improves speech hearing in aged patients. The results of the study give reason to recommend the treatment with tanakan for the elderly patients presenting with either presbiacusis or normal tonal hearing.

[Comparison of the residual hearing on the profound hearing-impaired children with the hearing aids and cochlear implants]

OBJECTIVE

To compare the hearing test data of the profound hearing-impaired children with the hearing aids and with cochlear implants; to find out the useful method to measure the residual hearing.

METHOD

Twenty-two profound hearing-impaired children participated in the study with complete set of hearing test and verbal rehabilitation file. Ten children fitted hearing aids and underwent verbal rehabilitation more than 3 months. Among the other 12 children with cochlear implants, 10 children fell in the same year range with the hearing aid patients. The children with hearing aids were divided into two groups according to the achievement of the verbal rehabilitation. ASSR threshold and pure- tone threshold were compared between the groups.

RESULT

(1) ASSR test: 7 children (14 ears) with hearing aids achieved good verbal representation, in which ASSR threshold can be recorded on 2.71 frequency on average [(110.92 +/- 7.43) dB HL]. Among 3 children with hearing aids representing poor verbal achievement and 5 children with additional cochlear implant because of the poor verbal achievement with hearing aids, only 1.06 frequency had response of ASSR test [(110.88 +/- 48.52 ) dB HL]. (2) Pure tone audiometry: the average threshold of the 7 children with good representation was (96.11 +/- 7.81) dB HL, and the threshold on 3 frequency were less than 100 dB HL on average. The average threshold of the other 3 children with poor verbal achievement was (112.19 +/- 5.15) dB HL, and none of the frequency threshold was 100 dB HL.

CONCLUSION

The number of the frequency with the response of ASSR and the threshold < or =100 dB HL of pure tone audiometry is an effective indication of the useful residual hearing.

Neuro-otologic manifestations of multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) has numerous neurologic signs and symptoms, including hearing impairment. The reports concerning the type and severity of hearing loss in MS patients vary and little is known about an association of the disease characteristics with changes in hearing status.

OBJECTIVE

To find the otologic and neuro-otologic manifestations of MS with the use of routine hearing assessment tools.

METHODS

The presence of neuro-otologic signs and symptoms were studied in 30 patients diagnosed with MS. Patients underwent pure tone audiometry, speech audiometry and acoustic brain stem response (ABR) tests. The results were compared with 30 healthy age and sex matched controls.

RESULTS

The most common finding was sensory-neural hearing loss followed by dizziness and nystagmus. The shape of the audiogram and severity of hearing loss was associated with both chronicity and disease activity. There were abnormal latencies in ABR waves which were more significant with high velocity stimulus.

CONCLUSION

Hearing status deserves careful attention in MS patients. It may be used as a diagnostic means or an indicator for evaluating the characteristics of the underlying disease.

Non-verbal visual reinforcement affects speech audiometry in the elderly

The purpose of this study was to investigate how non-verbal visual reinforcement provided by the audiologist during speech testing influences performance in the elderly. Thirty-two volunteers with age-related hearing loss with or without dual sensory-impairment (DSI), were administered a speech audiometry test in which they repeated lists of ten disyllabic words in two different conditions, namely with and without visual reinforcement. In the conditions of "with visual reinforcement", the tester provided non-verbal cues to acknowledge the response of each participant. The "visual reinforcement" condition did not apparently provide any significant variation in the results. However, when we considered the group of patients without DSI, the non-verbal "visual reinforcement" resulted in better scores (p < 0.001). Non-verbal visual reinforcement may influence speech audiometry results in the elderly. During speech testing of elderly people with age-related hearing loss, audiologists should always remember to administer visual reinforcement to the patients in order to remove a possible confounding factor from audiological evaluation.

Hearing aid effectiveness after aural rehabilitation - individual versus group (HEARING) trial: RCT design and baseline characteristics

BACKGROUND

Hearing impairment is the most common body system disability in veterans. In 2008, nearly 520,000 veterans had a disability for hearing loss through the Department of Veterans Affairs (VA). Changes in eligibility for hearing aid services, along with the aging population, contributed to a greater than 300% increase in the number of hearing aids dispensed from 1996 to 2006. In 2006, the VA committed to having no wait times for patient visits while providing quality clinically-appropriate care. One approach to achieving this goal is the use of group visits as an alternative to individual visits. We sought to determine: 1) if group hearing aid fitting and follow-up visits were at least as effective as individual visits, and 2) whether group visits lead to cost savings through the six month period after the hearing aid fitting. We describe the rationale, design, and characteristics of the baseline cohort of the first randomized clinical trial to study the impact of group versus individual hearing aid fitting and follow-up visits.

METHODS

Participants were recruited from the VA Puget Sound Health Care System Audiology Clinic. Eligible patients had no previous hearing aid use and monaural or binaural air-conduction hearing aids were ordered at the evaluation visit. Participants were randomized to receive the hearing aid fitting and the hearing aid follow-up in an individual or group visit. The primary outcomes were hearing-related function, measured with the first module of the Effectiveness of Aural Rehabilitation (Inner EAR), and hearing aid adherence. We tracked the total cost of planned and unplanned audiology visits over the 6-month interval after the hearing aid fitting.

DISCUSSION

A cohort of 659 participants was randomized to receive group or individual hearing aid fitting and follow-up visits. Baseline demographic and self-reported health status and hearing-related measures were evenly distributed across the treatment arms.Outcomes after the 6-month follow-up period are needed to determine if group visits were as least as good as those for individual visits and will be reported in subsequent publication.

TRIAL REGISTRATION

NCT00260663.

A Swedish version of the Hearing In Noise Test (HINT) for measurement of speech recognition

A Swedish Hearing In Noise Test (HINT), consisting of everyday sentences to be used in an adaptive procedure to estimate the speech recognition thresholds in noise and quiet, has been developed. The material consists of 250 sentences, with a length of five to nine syllables, normalized for naturalness, difficulty and reliability. The sentences were recorded with a female speaker. From the sentences, 25 phonemically balanced lists were created. All lists fluctuate less than 1 dB of the overall mean. The standard deviation of the test-retest difference is 0.94 dB when testing with one list, and decreases to 0.68 dB and 0.56 dB for two and three lists, respectively. The average speech recognition thresholds in noise for the Swedish sentences were -3.0 dB signal/noise ratio (SD=1.1 dB). The present study has resulted in a well-defined and internationally comparable set of sentences, which can be used in Swedish audiological rehabilitation and research to measure speech recognition in noise and quiet.

The influence of visual feedback on closed-set word test performance over time

Closed-set word tests can be implemented with or without trial-by-trial visual feedback. Feedback is considered to increase subject motivation yet its influence on performance is unknown. The aim of this study was to compare performance on the Four Alternative Auditory Feature (FAAF) test with and without visual feedback over a 24-week period following fitting of a hearing aid. A total of 32 elderly subjects were recruited as new users and fitted monaurally with the same model of linear, programmable hearing aid that provided in excess of 20 dB insertion gain at 2-4 kHz. Half of the subjects were provided with visual feedback. In these subjects, mean performance increased by 5% across the study period. The improvement in performance over time was statistically significant on analysis of variance (p < 0.05). Mean performance did not increase in the remaining subjects who were not provided with feedback. If closed-set word tests are to be used with visual feedback to measure changes over time, the potentially confounding effects of practice must be controlled carefully. Alternatively, omitting feedback leads to simpler experimental designs.

The viability of speech-in-noise audiometric screening using domestic audio equipment

Speech-in-noise audiometry has potential application as a low-cost, self-screening test for sensorineural hearing loss. To realize this potential, the influence of variations in audio equipment and listening environment need assessment. The present study assessed: 1) the frequency response and distortion produced by a wide range of commercially available audio equipment; 2) the effects of such variations upon test results with normally hearing subjects using a simple, open-set, word-identification test; 3) the effect of distortion on the speech reception threshold using digitally applied distortion; and 4) the reliability of the test in listening environments with different levels of reverberation. In addition, preliminary tests were conducted with elderly listeners. The results indicate that variations in equipment have negligible effects on speech-in-noise audiometry. The only factor that substantially elevated normally hearing listeners' thresholds was high levels of room reverberation when using loudspeaker presentation. Variations in equipment and environment thus present no significant obstacle to the development of a self-administered audiometric screening test based on speech in noise.

The Listening in Spatialized Noise test: Normative data for children

The Listening in Spatialized Noise test (LISN) produces a three-dimensional auditory environment under headphones, using only a PC and an audiometer, and was designed to provide an ecologically valid assessment of auditory figure-ground skills in children. The listener is required to indicate the intelligibility level of a story presented at 0 degree azimuth, in the presence of distracter sentences simultaneously presented at either 0 degree or +/- 90 degrees azimuth. Various measures assess the extent to which either spatial, vocal, or spatial and vocal cues combined, increase a listener's ability to comprehend the story, without being affected by differences between participants in variables such as linguistic skills. There was a trend of improved performance with increasing age for 48 normally hearing seven-, eight-, and nine-year-olds, and sixteen adults. Whereas some significant differences were found between adults and children, there were no significant differences in performance between the seven-, eight-, and nine-year-olds on any measure, and no significant gender or practice effects were observed. Future studies on children with suspected auditory processing disorder were considered warranted.

Auditory processing disorders in adults and children: Evaluation of a test battery: Desórdenes del procesamiento auditivo en adultos y niños; evaluación de una batería de pruebas

A Dutch test battery comprising six different tests for auditory processing disorders was evaluated in a group of 49 adults and children (age 8-57 years) with auditory complaints despite normal audiometric thresholds. Percentile scores were derived from normal control groups (n = 132) to determine whether a subject passed or failed a test. A composite score was computed to reflect a general score on all the auditory processing tests. In order to gain insight into underlying auditory processes, factor analysis was performed. Normal scores on all the tests were seen in five subjects. The remaining 44 subjects had at least one test score that was below the cut-off point (10th percentile). Factor analysis provided evidence for a model comprising four auditory components: auditory sequencing, word recognition in noise, auditory closure, and auditory patterning. This model could be useful in the interpretation of scoring patterns. Although there were some differences in scoring patterns between the children and adults, the test battery proved to be useful in both groups.

Speech production variability in fricatives of children and adults: results of functional data analysis

This study investigates token-to-token variability in fricative production of 5 year olds, 10 year olds, and adults. Previous studies have reported higher intrasubject variability in children than adults, in speech as well as nonspeech tasks, but authors have disagreed on the causes and implications of this finding. The current work assessed the characteristics of age-related variability across articulators (larynx and tongue) as well as in temporal versus spatial domains. Oral airflow signals, which reflect changes in both laryngeal and supralaryngeal apertures, were obtained for multiple productions of /h s z/. The data were processed using functional data analysis, which provides a means of obtaining relatively independent indices of amplitude and temporal (phasing) variability. Consistent with past work, both temporal and amplitude variabilities were higher in children than adults, but the temporal indices were generally less adultlike than the amplitude indices for both groups of children. Quantitative and qualitative analyses showed considerable speaker- and consonant-specific patterns of variability. The data indicate that variability in /s/ may represent laryngeal as well as supralaryngeal control and further that a simple random noise factor, higher in children than in adults, is insufficient to explain developmental differences in speech production variability.

Comparison of middle latency responses in presbycusis patients with two different speech recognition scores

OBJECTIVE

The purpose of this study is to evaluate whether the middle latency responses (MLR) can be used for an objective differentiation of patients with presbycusis having relatively good (Group I) and relatively poor speech recognition scores (Group II).

METHODS

All the participants of these groups had high frequency down-sloping hearing loss with an average of 26-60 dB HL. Data were collected from two described study groups and a control group, using pure tone audiometry, monosyllabic phonetically balanced word and synthetic sentence identification, as well as MLR. The study groups were compared with the control group.

RESULTS

When patients in Group I were compared with the control group, only ipsilateral Na latency of middle latency evoked response was statistically significant in the right ear whereas ipsilateral Na latency in the right ear, ipsilateral and contralateral Na latency in the left ear of the patients in Group II were statistically significant.

CONCLUSION

Thus, as an objective complementary tool for the evaluation of the speech perception ability of the patients with presbycusis, Na latency of MLR may be used in combination with the speech discrimination tests.