scholarly journals A Set of Time-and-Frequency-Localized Short-Duration Speech-Like Stimuli for Assessing Hearing-Aid Performance via Cortical Auditory-Evoked Potentials

2019 ◽  
Vol 23 ◽  
pp. 233121651988556
Author(s):  
Michael A. Stone ◽  
Anisa Visram ◽  
James M. Harte ◽  
Kevin J. Munro
Keyword(s):  
Evoked Potentials ◽  
Short Duration ◽  
Hearing Aids ◽  
Clinical Setting ◽  
Auditory Evoked Potentials ◽  
British Society ◽  
Worst Case ◽  
Electrophysiological Response ◽  
Digital Hearing Aids ◽  
Cortical Auditory Evoked Potentials

Short-duration speech-like stimuli, for example, excised from running speech, can be used in the clinical setting to assess the integrity of the human auditory pathway at the level of the cortex. Modeling of the cochlear response to these stimuli demonstrated an imprecision in the location of the spectrotemporal energy, giving rise to uncertainty as to what and when of a stimulus caused any evoked electrophysiological response. This article reports the development and assessment of four short-duration, limited-bandwidth stimuli centered at low, mid, mid-high, and high frequencies, suitable for free-field delivery and, in addition, reproduction via hearing aids. The durations were determined by the British Society of Audiology recommended procedure for measuring Cortical Auditory-Evoked Potentials. The levels and bandwidths were chosen via a computational model to produce uniform cochlear excitation over a width exceeding that likely in a worst-case hearing-impaired listener. These parameters produce robustness against errors in insertion gains, and variation in frequency responses, due to transducer imperfections, room modes, and age-related variation in meatal resonances. The parameter choice predicts large spectral separation between adjacent stimuli on the cochlea. Analysis of the signals processed by examples of recent digital hearing aids mostly show similar levels of gain applied to each stimulus, independent of whether the stimulus was presented in isolation, bursts, continuous, or embedded in continuous speech. These stimuli seem to be suitable for measuring hearing-aided Cortical Auditory-Evoked Potentials and have the potential to be of benefit in the clinical setting.

New possibility for measuring the cortical auditory evoked potentials: the HEARLab

2014 ◽  
Vol 155 (38) ◽  
pp. 1524-1529
Author(s):  
Ádám Bach ◽  
Ferenc Tóth ◽  
Vera Matievics ◽  
József Géza Kiss ◽  
József Jóri ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Evoked Potentials ◽  
Auditory System ◽  
Hearing Aids ◽  
Pure Tone ◽  
Auditory Evoked Potentials ◽  
Normal Hearing ◽  
Speech Stimuli ◽  
Novel Method ◽  
Cortical Auditory Evoked Potentials

Introduction: Cortical auditory evoked potentials can provide objective information about the highest level of the auditory system. Aim: The purpose of the authors was to introduce a new tool, the “HEARLab” which can be routinely used in clinical practice for the measurement of the cortical auditory evoked potentials. In addition, they wanted to establish standards of the analyzed parameters in subjects with normal hearing. Method: 25 adults with normal hearing were tested with speech stimuli, and frequency specific examinations were performed utilizing pure tone stimuli. Results: The findings regarding the latency and amplitude analyses of the evoked potentials confirm previously published results of this novel method. Conclusions: The HEARLAb can be a great help when performance of the conventional audiological examinations is complicated. The examination can be performed in uncooperative subjects even in the presence of hearing aids. The test is frequency specific and does not require anesthesia. Orv. Hetil., 2014, 155(38), 1524–1529.

scholarly journals Electroacoustic Comparison of Hearing Aid Output of Phonemes in Running Speech versus Isolation: Implications for Aided Cortical Auditory Evoked Potentials Testing

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Vijayalakshmi Easwar ◽  
David W. Purcell ◽  
Susan D. Scollie
Keyword(s):  
Evoked Potentials ◽  
Hearing Aids ◽  
Auditory Evoked Potentials ◽  
Hearing Aid ◽  
Conversational Speech ◽  
Individual Basis ◽  
The Past ◽  
Cortical Auditory Evoked Potentials

Background. Functioning of nonlinear hearing aids varies with characteristics of input stimuli. In the past decade, aided speech evoked cortical auditory evoked potentials (CAEPs) have been proposed for validation of hearing aid fittings. However, unlike in running speech, phonemes presented as stimuli during CAEP testing are preceded by silent intervals of over one second. Hence, the present study aimed to compare if hearing aids process phonemes similarly in running speech and in CAEP testing contexts.Method. A sample of ten hearing aids was used. Overall phoneme level and phoneme onset level of eight phonemes in both contexts were compared at three input levels representing conversational speech levels.Results. Differences of over 3 dB between the two contexts were noted in one-fourth of the observations measuring overall phoneme levels and in one-third of the observations measuring phoneme onset level. In a majority of these differences, output levels of phonemes were higher in the running speech context. These differences varied across hearing aids.Conclusion. Lower output levels in the isolation context may have implications for calibration and estimation of audibility based on CAEPs. The variability across hearing aids observed could make it challenging to predict differences on an individual basis.

The Use of Cortical Auditory Evoked Potentials to Evaluate Neural Encoding of Speech Sounds in Adults

2006 ◽  
Vol 17 (08) ◽  
pp. 559-572 ◽  
Author(s):  
Katrina Agung ◽  
Suzanne C. Purdy ◽  
Catherine M. McMahon ◽  
Philip Newall
Keyword(s):  
Evoked Potentials ◽  
Hearing Aids ◽  
Auditory Evoked Potentials ◽  
Speech Sounds ◽  
Speech Discrimination ◽  
Neural Encoding ◽  
Speech Stimuli ◽  
Speech Encoding ◽  
Cortical Level ◽  
Cortical Auditory Evoked Potentials

There has been considerable recent interest in the use of cortical auditory evoked potentials (CAEPs) as an electrophysiological measure of human speech encoding in individuals with normal as well as impaired auditory systems. The development of such electrophysiological measures such as CAEPs is important because they can be used to evaluate the benefits of hearing aids and cochlear implants in infants, young children, and adults that cannot cooperate for behavioral speech discrimination testing. The current study determined whether CAEPs produced by seven different speech sounds, which together cover a broad range of frequencies across the speech spectrum, could be differentiated from each other based on response latency and amplitude measures. CAEPs were recorded from ten adults with normal hearing in response to speech stimuli presented at a conversational level (65 dB SPL) via a loudspeaker. Cortical responses were reliably elicited by each of the speech sounds in all participants. CAEPs produced by speech sounds dominated by high-frequency energy were significantly different in amplitude from CAEPs produced by sounds dominated by lower-frequency energy. Significant effects of stimulus duration were also observed, with shorter duration stimuli producing larger amplitudes and earlier latencies than longer duration stimuli. This research demonstrates that CAEPs can be reliably evoked by sounds that encompass the entire speech frequency range. Further, CAEP latencies and amplitudes may provide an objective indication that spectrally different speech sounds are encoded differently at the cortical level.

scholarly journals Cortical Auditory Evoked Potentials in Children with a Hearing Loss: A Pilot Study

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Amineh Koravand ◽  
Benoît Jutras ◽  
Maryse Lassonde
Keyword(s):  
Hearing Loss ◽  
Evoked Potentials ◽  
Hearing Aids ◽  
Auditory Processing ◽  
Auditory Evoked Potentials ◽  
Group Differences ◽  
Central Auditory Processing ◽  
Significant Group ◽  
Children With Hearing Loss ◽  
Cortical Auditory Evoked Potentials

Objective. This study examined the patterns of neural activity in the central auditory system in children with hearing loss.Methods. Cortical potentials and mismatch responses (MMRs) were recorded from ten children aged between 9 and 10 years: five with hearing loss and five with normal hearing in passive oddball paradigms using verbal and nonverbal stimuli.Results. Results indicate a trend toward larger P1 amplitude, a significant reduction in amplitude, and latency of N2 in children with hearing loss compared to control. No significant group differences were observed for the majority of the MMRs conditions.Conclusions. Data suggest that the reduced auditory input affects the pattern of cortical-auditory-evoked potentials in children with a mild to moderately severe hearing loss. Results suggest maturational delays and/or deficits in central auditory processing in children with hearing loss, as indicated by the neurophysiological markers P1 and N2. In contrast, negative MMR data suggest that the amplification provided by the hearing aids could have allowed children with hearing loss to develop adequate discriminative abilities.

Cortical auditory evoked potentials in children using hearing aids

2012 ◽  
Vol 10 (3) ◽  
pp. 132-142
Author(s):  
Enaas A. Kolkaila ◽  
Afaf A. Emara ◽  
Takwa A. Gabr
Keyword(s):  
Evoked Potentials ◽  
Hearing Aids ◽  
Auditory Evoked Potentials ◽  
Cortical Auditory Evoked Potentials

scholarly journals Assessing the applications of cortical auditory evoked potentials as a biomarker in children with hearing aids

2014 ◽  
Vol 30 (1) ◽  
pp. 38
Author(s):  
HodaMahmoud Weheiba ◽  
IsmailZohdi Mostafa ◽  
MohamedIbrahim Shabana ◽  
AmiraMaged El Shennawy
Keyword(s):  
Evoked Potentials ◽  
Hearing Aids ◽  
Auditory Evoked Potentials ◽  
Cortical Auditory Evoked Potentials

Cortical Auditory-Evoked Potentials (CAEPs) in Adults in Response to Filtered Speech Stimuli

2013 ◽  
Vol 24 (09) ◽  
pp. 807-822 ◽  
Author(s):  
Lyndal Carter ◽  
Harvey Dillon ◽  
John Seymour ◽  
Mark Seeto ◽  
Bram Van Dun
Keyword(s):  
Hearing Loss ◽  
Evoked Potentials ◽  
Hearing Aids ◽  
Auditory Evoked Potentials ◽  
Hearing Aid ◽  
Speech Sounds ◽  
Sensation Level ◽  
Behavioral Threshold ◽  
Speech Stimuli ◽  
Cortical Auditory Evoked Potentials

Background: Previous studies have demonstrated that cortical auditory-evoked potentials (CAEPs) can be reliably elicited in response to speech stimuli in listeners wearing hearing aids. It is unclear, however, how close to the aided behavioral threshold (i.e., at what behavioral sensation level) a sound must be before a cortical response can reliably be detected. Purpose: The purpose of this study was to systematically examine the relationship between CAEP detection and the audibility of speech sounds (as measured behaviorally), when the listener is wearing a hearing aid fitted to prescriptive targets. A secondary aim was to investigate whether CAEP detection is affected by varying the frequency emphasis of stimuli, so as to simulate variations to the prescribed gain-frequency response of a hearing aid. The results have direct implications for the evaluation of hearing aid fittings in nonresponsive adult clients, and indirect implications for the evaluation of hearing aid fittings in infants. Research Design: Participants wore hearing aids while listening to speech sounds presented in a sound field. Aided thresholds were measured, and cortical responses evoked, under a range of stimulus conditions. The presence or absence of CAEPs was determined by an automated statistic. Study Sample: Participants were adults (6 females and 4 males). Participants had sensorineural hearing loss ranging from mild to severe-profound in degree. Data Collection and Analysis: Participants' own hearing aids were replaced with a test hearing aid, with linear processing, during assessments. Pure-tone thresholds and hearing aid gain measurements were obtained, and a theoretical prediction of speech stimulus audibility for each participant (similar to those used for audibility predictions in infant hearing aid fittings) was calculated. Three speech stimuli, (/m/, /t/, and /g/) were presented aided (monaurally, nontest ear occluded), free field, under three conditions (+4 dB/octave, −4 dB/octave, and without filtering), at levels of 40, 50, and 60 dB SPL (measured for the unfiltered condition). Behavioral thresholds were obtained, and CAEP recordings were made using these stimuli. The interaction of hearing loss, presentation levels, and filtering conditions resulted in a range of CAEP test behavioral sensation levels (SLs), from −25 to +40 dB. Results: Statistically significant CAEPs (p < .05) were obtained for virtually every presentation where the behavioral sensation level was >10 dB, and for only 5% of occasions when the sensation level was negative. In these (“false-positive”) cases, the greatest (negative) sensation level at which a CAEP was judged to be present was −6 dB SL. Conclusions: CAEPs are a sensitive tool for directly evaluating the audibility of speech sounds, at least for adult listeners. CAEP evaluation was found to be more accurate than audibility predictions, based on threshold and hearing aid response measures.

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