Threshold Estimation Using “Chained Stimuli” for Cortical Auditory Evoked Potentials in Individuals With Normal Hearing and Hearing Impairment

2019 ◽  
Vol 28 (2S) ◽  
pp. 428-436
Author(s):  
Mohan Kumar Kalaiah ◽  
Sanjana Poovaiah ◽  
Usha Shastri

Purpose We investigated the utility of chained stimuli for threshold estimation using cortical auditory evoked potentials (CAEPs) in individuals with normal hearing sensitivity and hearing loss. The effect of the order of frequency in chained stimuli on CAEPs was also studied. Method Seventeen individuals with normal hearing and 17 individuals with mild to severe sensorineural hearing loss participated in the study. In individuals with normal hearing, CAEPs were recorded at 80 dB nHL for 4 chained stimuli with different orders of frequencies within them (Chained Stimuli 1 [CS1]: 500, 1000, 2000, 4000 Hz; Chained Stimuli 2: 4000, 2000, 1000, 500 Hz; Chained Stimuli 3: 500, 2000, 1000, 4000 Hz; Chained Stimuli 4: 4000, 1000, 2000, 500 Hz). CAEP threshold estimation was carried out using CS1 in both groups and was compared with behavioral pure-tone thresholds. Results CS1 elicited the largest amplitude responses at low and mid frequencies, whereas all 4 stimuli elicited similar amplitude responses at high frequencies. CAEP thresholds were generally within 10–20 dB above the participants' behavioral threshold in both groups. The difference between CAEP threshold and behavioral threshold was less for individuals with hearing loss compared to individuals with normal hearing. There was a significant positive correlation between CAEP threshold and behavioral threshold at all the frequencies. Conclusions CS1 could be used to elicit CAEPs for threshold estimation in adult participants with normal hearing and hearing loss of varied degrees with theoretically reduced testing time. The actual time reduction using chained stimuli and the correction factor to be applied to estimate behavioral threshold can be studied in future investigations.

2013 ◽  
Vol 24 (09) ◽  
pp. 807-822 ◽  
Author(s):  
Lyndal Carter ◽  
Harvey Dillon ◽  
John Seymour ◽  
Mark Seeto ◽  
Bram Van Dun

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.


2019 ◽  
Vol 62 (4S) ◽  
pp. 1099-1116 ◽  
Author(s):  
Lindsey Roque ◽  
Casey Gaskins ◽  
Sandra Gordon-Salant ◽  
Matthew J. Goupell ◽  
Samira Anderson

Purpose Degraded temporal processing associated with aging may be a contributing factor to older adults' hearing difficulties, especially in adverse listening environments. This degraded processing may affect the ability to distinguish between words based on temporal duration cues. The current study investigates the effects of aging and hearing loss on cortical and subcortical representation of temporal speech components and on the perception of silent interval duration cues in speech. Method Identification functions for the words DISH and DITCH were obtained on a 7-step continuum of silence duration (0–60 ms) prior to the final fricative in participants who are younger with normal hearing (YNH), older with normal hearing (ONH), and older with hearing impairment (OHI). Frequency-following responses and cortical auditory-evoked potentials were recorded to the 2 end points of the continuum. Auditory brainstem responses to clicks were obtained to verify neural integrity and to compare group differences in auditory nerve function. A multiple linear regression analysis was conducted to determine the peripheral or central factors that contributed to perceptual performance. Results ONH and OHI participants required longer silence durations to identify DITCH than did YNH participants. Frequency-following responses showed reduced phase locking and poorer morphology, and cortical auditory-evoked potentials showed prolonged latencies in ONH and OHI participants compared with YNH participants. No group differences were noted for auditory brainstem response Wave I amplitude or Wave V/I ratio. After accounting for the possible effects of hearing loss, linear regression analysis revealed that both midbrain and cortical processing contributed to the variance in the DISH–DITCH perceptual identification functions. Conclusions These results suggest that age-related deficits in the ability to encode silence duration cues may be a contributing factor in degraded speech perception. In particular, degraded response morphology relates to performance on perceptual tasks based on silence duration contrasts between words.


2014 ◽  
Vol 155 (38) ◽  
pp. 1524-1529
Author(s):  
Ádám Bach ◽  
Ferenc Tóth ◽  
Vera Matievics ◽  
József Géza Kiss ◽  
József Jóri ◽  
...  

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.


2016 ◽  
Vol 37 (01) ◽  
pp. 036-052 ◽  
Author(s):  
Bram Van Dun ◽  
Alison King ◽  
Lyndal Carter ◽  
Wendy Pearce ◽  
Simone Punch

2016 ◽  
Vol 27 (05) ◽  
pp. 406-415 ◽  
Author(s):  
Fabrice Bardy ◽  
Jessica Sjahalam-King ◽  
Bram Van Dun ◽  
Harvey Dillon

Purpose: To determine if one-octave multitone (MT) stimuli increase the amplitude of cortical auditory-evoked potentials (CAEPs) in individuals with a hearing loss when compared to standard pure-tone (PT) stimuli and narrow-band noise (NBN). Research Design: CAEPs were obtained from 16 hearing-impaired adults in response to PT and MT auditory stimuli centered around 0.5, 1, 2, and 4 kHz and NBN centered around 1 and 2 kHz. Hearing impairment ranged from a mild to a moderate hearing loss in both ears. Auditory stimuli were monaurally delivered through insert earphones at 10 and 20 dB above threshold. The root mean square amplitude of the CAEP and the detectability of the responses using Hotelling’s T2 were calculated and analyzed. Results: CAEP amplitudes elicited with MT stimuli were on average 29% larger than PT stimuli for frequencies centered around 1, 2, and 4 kHz. No significant difference was found for responses to 0.5-kHz stimuli. Significantly higher objective detection scores were found for MT when compared to PT. For the 1- and 2-kHz stimuli, the CAEP amplitudes to NBN were not significantly different to those evoked by PT but a significant difference was found between MT stimuli and both NBN and PT. The mean detection sensitivity of MT for the four frequencies was 80% at 10 dB SL and 95% at 20 dB SL, and was comparable with detection sensitivities observed in normal-hearing participants. Conclusions: Using MT stimuli when testing CAEPs in adults with hearing impairment showed larger amplitudes and a higher objective detection sensitivity compared to using traditional PT stimuli for frequencies centered around 1, 2, and 4 kHz. These findings suggest that MT stimuli are a clinically useful tool to increase the efficiency of frequency-specific CAEP testing in adults with hearing impairment.


2003 ◽  
Vol 17 (4) ◽  
pp. 189-194 ◽  
Author(s):  
Sirkku K. Salo ◽  
A. Heikki Lang ◽  
Altti J. Salmivalli ◽  
Reijo K. Johansson ◽  
Maija S. Peltola

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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