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.

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.

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.

scholarly journals Aided Electrophysiology Using Direct Audio Input: Effects of Amplification and Absolute Signal Level

2016 ◽  
Vol 25 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Ingyu Chun ◽  
Curtis J. Billings ◽  
Christi W. Miller ◽  
Kelly L. Tremblay
Keyword(s):  
Young Adults ◽  
Evoked Potentials ◽  
Pure Tone ◽  
Auditory Evoked Potentials ◽  
Hearing Aid ◽  
Normal Hearing ◽  
Signal To Noise ◽  
Noise Floor ◽  
Linear Analog ◽  
Cortical Auditory Evoked Potentials

Purpose This study investigated (a) the effect of amplification on cortical auditory evoked potentials (CAEPs) at different signal levels when signal-to-noise ratios (SNRs) were equated between unaided and aided conditions, and (b) the effect of absolute signal level on aided CAEPs when SNR was held constant. Method CAEPs were recorded from 13 young adults with normal hearing. A 1000-Hz pure tone was presented in unaided and aided conditions with a linear analog hearing aid. Direct audio input was used, allowing recorded hearing aid noise floor to be added to unaided conditions to equate SNRs between conditions. An additional stimulus was created through scaling the noise floor to study the effect of signal level. Results Amplification resulted in delayed N1 and P2 peak latencies relative to the unaided condition. An effect of absolute signal level (when SNR was constant) was present for aided CAEP area measures, such that larger area measures were found at higher levels. Conclusion Results of this study further demonstrate that factors in addition to SNR must also be considered before CAEPs can be used to clinically to measure aided thresholds.

scholarly journals Analysis of the Effect of Musical Stimulation on Cortical Auditory Evoked Potentials

2018 ◽  
Vol 23 (01) ◽  
pp. 031-035
Author(s):  
Daiane Lima ◽  
Simone Regaçone ◽  
Anna Oliveira ◽  
Yara Alcântara ◽  
Eduardo Chagas ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Auditory System ◽  
Repeated Measures ◽  
Auditory Evoked Potentials ◽  
P Value ◽  
Mixed Analysis ◽  
Sphericity Test ◽  
Significant Difference ◽  
Healthy Female ◽  
Cortical Auditory Evoked Potentials

Introduction Cortical auditory evoked potentials (CAEPs) are bioelectric responses that occur from acoustic stimulations, and they assess the functionality of the central auditory system. Objective The objective of the present study was to analyze the effect of musical stimulation on CAEPs. Methods The sample consisted of 42 healthy female subjects, aged between 18 and 24 years, divided into two groups – G1: without musical stimulation prior to the CAEP examination; and G2: with stimulation prior to the examination. In both groups, as a pre-collection procedure, the complete basic audiological evaluation was performed. For the musical stimulation performed in G2, we used an MP4 player programmed to play Pachelbel's “Canon in D Major” for five minutes prior to the CAEP examination. To analyze the effect on the groups, the ear side and the ide–group interaction , a mixed analysis of variance (ANOVA) of repeated measures was performed. Box M test and Mauchly sphericity test were also performed. Results Test differences were considered statistically significant when the p-value was < 0.05 (5%). Thus, it was possible to observe that there was a statistically significant difference of the P2 component characterized by the decrease in the amplitude of response in the left ear in G2 when comparing the responses of CAEP with and without prior musical stimulation. Conclusion The result of the present study enabled us to conclude that there was a change in the response of CAEPs with musical stimulation.

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.

Contralateral White Noise Masking Affects Auditory N1 and P2 Waves Differently

2003 ◽  
Vol 17 (4) ◽  
pp. 189-194 ◽  
Author(s):  
Sirkku K. Salo ◽  
A. Heikki Lang ◽  
Altti J. Salmivalli ◽  
Reijo K. Johansson ◽  
Maija S. Peltola
Keyword(s):  
Evoked Potentials ◽  
White Noise ◽  
Auditory Evoked Potentials ◽  
Normal Hearing ◽  
Mask Condition ◽  
Noise Masking ◽  
The Right ◽  
Cortical Auditory Evoked Potentials ◽  
Contralateral Masking ◽  
Hearing System

Abstract In this study, we examined the effect of contralateral masking on cortical auditory evoked potentials N1 (modal-specific slowly adapting component) and P2 at different masking intensities. N1 and P2 potentials were recorded from 15 subjects with normal hearing using 500Hz tone pips (intensity 65dB HL, duration 100ms, ISI 1s) presented to the right ear. Continuous white noise was delivered to the left ear at the intensities of 35, 50, 65, or 75dB effective masking level (EML), as well as a no-mask condition. The electrodes F3, Fz, F4, C3, Cz, C4, and Pz were used. The results show that N1 amplitude was significantly attenuated and, in contrast, P2 amplitude was significantly increased, with contralateral 75dB EML white noise. N1P2 peak to peak amplitude was not affected by masking, nor were the peak latencies. Thus, contralateral masking affects the exogenous cortical evoked N1 and P2 curves differently. We suggest that the effect is mediated by the efferent hearing system. The effect of ≤ 50dB EML contralateral white noise masking is so small that it should not affect clinical recordings.

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