Neurophysiological aspects of brainstem processing of speech stimuli in audiometric-normal geriatric population

2016 ◽  
Vol 131 (3) ◽  
pp. 239-244 ◽  
Author(s):  
M S Ansari ◽  
R Rangasayee ◽  
M A H Ansari

AbstractObjective:Poor auditory speech perception in geriatrics is attributable to neural de-synchronisation due to structural and degenerative changes of ageing auditory pathways. The speech-evoked auditory brainstem response may be useful for detecting alterations that cause loss of speech discrimination. Therefore, this study aimed to compare the speech-evoked auditory brainstem response in adult and geriatric populations with normal hearing.Methods:The auditory brainstem responses to click sounds and to a 40 ms speech sound (the Hindi phoneme |da|) were compared in 25 young adults and 25 geriatric people with normal hearing. The latencies and amplitudes of transient peaks representing neural responses to the onset, offset and sustained portions of the speech stimulus in quiet and noisy conditions were recorded.Results:The older group had significantly smaller amplitudes and longer latencies for the onset and offset responses to |da| in noisy conditions. Stimulus-to-response times were longer and the spectral amplitude of the sustained portion of the stimulus was reduced. The overall stimulus level caused significant shifts in latency across the entire speech-evoked auditory brainstem response in the older group.Conclusion:The reduction in neural speech processing in older adults suggests diminished subcortical responsiveness to acoustically dynamic spectral cues. However, further investigations are needed to encode temporal cues at the brainstem level and determine their relationship to speech perception for developing a routine tool for clinical decision-making.

2015 ◽  
Vol 24 (4) ◽  
pp. 573-583 ◽  
Author(s):  
Gabriel Anne Bargen

Purpose The aim of this study was to assess the use of the chirp stimulus to record auditory brainstem responses in the pediatric population via a traditional review. Method An electronic search of the literature and a hand search of the literature were conducted. Studies that utilized chirp stimuli within the pediatric population that met all of the inclusion criteria were included in this review. Qualitative synthesis and interpretation of the data were completed. Results Seven studies that met the inclusion criteria were included in the review. Chirp stimuli produce auditory brainstem response (ABR) waveform amplitudes in children similar to those in adults when presented at moderate to low frequency levels. Latency data from chirp stimuli are not consistent when stimulus presentation rates are altered. Test–retest reliability when using the chirp stimulus was found to be good, as were sensitivity and specificity of chirp-evoked ABRs utilized in a newborn hearing screening protocol. Conclusion Reviewed studies indicated that when presented at 60 dB nHL or lower, broadband chirp–generated ABRs have larger amplitudes than click-generated ABRs in children with normal hearing. Utilization of chirp stimuli decreases test time because waveforms are easier to detect with increased synchronization. Further research should focus on correlating chirp thresholds with behavioral hearing thresholds. Given the variance of results in these select studies, future research should also evaluate latency findings and focus on developing normative data for infants with hearing impairment and normal hearing.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marina Saiz-Alía ◽  
Antonio Elia Forte ◽  
Tobias Reichenbach

Abstract People with normal hearing thresholds can nonetheless have difficulty with understanding speech in noisy backgrounds. The origins of such supra-threshold hearing deficits remain largely unclear. Previously we showed that the auditory brainstem response to running speech is modulated by selective attention, evidencing a subcortical mechanism that contributes to speech-in-noise comprehension. We observed, however, significant variation in the magnitude of the brainstem’s attentional modulation between the different volunteers. Here we show that this variability relates to the ability of the subjects to understand speech in background noise. In particular, we assessed 43 young human volunteers with normal hearing thresholds for their speech-in-noise comprehension. We also recorded their auditory brainstem responses to running speech when selectively attending to one of two competing voices. To control for potential peripheral hearing deficits, and in particular for cochlear synaptopathy, we further assessed noise exposure, the temporal sensitivity threshold, the middle-ear muscle reflex, and the auditory-brainstem response to clicks in various levels of background noise. These tests did not show evidence for cochlear synaptopathy amongst the volunteers. Furthermore, we found that only the attentional modulation of the brainstem response to speech was significantly related to speech-in-noise comprehension. Our results therefore evidence an impact of top-down modulation of brainstem activity on the variability in speech-in-noise comprehension amongst the subjects.


PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251287
Author(s):  
Alejandro Ianiszewski ◽  
Adrian Fuente ◽  
Jean-Pierre Gagné

Background Some evidence suggests that young adults exhibit a selective laterality of auditory brainstem response (ABR) elicited with speech stimuli. Little is known about such an auditory laterality in older adults. Objective The aim of this study was to investigate possible asymmetric auditory brainstem processing between right and left ear presentation in older adults. Methods Sixty-two older adults presenting with normal hearing thresholds according to their age and who were native speakers of Quebec French participated in this study. ABR was recorded using click and a 40-ms /da/ syllable. ABR was elicited through monaural right and monaural left stimulation. Latency and amplitude for click-and speech-ABR components were compared between right and left ear presentations. In addition, for the /da/ syllable, a fast Fourier transform analysis of the sustained frequency-following response (FFR) of the vowel was performed along with stimulus-to-response and right-left ear correlation analyses. Results No significant differences between right and left ear presentation were found for amplitudes and latencies of the click-ABR components. Significantly shorter latencies for right ear presentation as compared to left ear presentation were observed for onset and offset transient components (V, A and O), sustained components (D and E), and voiced transition components (C) of the speech-ABR. In addition, the spectral amplitude of the fundamental frequency (F0) was significantly larger for the left ear presentation than the right ear presentation. Conclusions Results of this study show that older adults with normal hearing exhibit symmetric encoding for click stimuli at the brainstem level between the right and left ear presentation. However, they present with brainstem asymmetries for the encoding of selective stimulus components of the speech-ABR between the right and left ear presentation. The right ear presentation of a /da/ syllable elicited reduced neural timing for both transient and sustained components compared to the left ear. Conversely, a stronger left ear F0 encoding was observed. These findings suggest that at a preattentive, sensory stage of auditory processing, older adults lateralize speech stimuli similarly to young adults.


1982 ◽  
Vol 25 (4) ◽  
pp. 528-535 ◽  
Author(s):  
Larry E. Humes ◽  
Marleen G. Ochs

In the first portion this study, the effects of two levels of contralateral masking on the auditory brainstem response (ABR) were investigated in 10 normal-hearing subjects. No significant changes were observed in the mean latency-intensity functions or the mean amplitude-intensity functions of this group of subjects when noise of various levels was added to the nontest ear. In the second portion of this study, ABRs were also recorded from the poorer ear of four subjects with a profound unilateral sensorineural hearing loss. Results from the latter group revealed a crossed-over wave V in all cases when the stimulus was delivered to the poorer ear and the nontest (better) ear was not masked. Contralateral masking obliterated this "crossed ABB" in all four unilaterally impaired subjects. These results provide support for the use of contralateral masking when recording from the poorer ear of subjects having asymmetrical hearing loss.


2020 ◽  
Vol 24 ◽  
pp. 233121652094613
Author(s):  
Kelly Dean ◽  
John H. Grose

The purpose of this study was to measure the binaural interaction component (BIC) derived from click-evoked auditory brainstem responses (ABRs) using stimuli configured to elicit the Precedence Effect. The hypothesis was that the contribution of binaural processing to echo suppression can be evidenced by a diminished or absent BIC associated with the echo. Ten normal-hearing young adults provided ABRs generated by sequences of click pairs. Results showed that BICs elicited by diotic clicks in isolation were obliterated when those diotic clicks were preceded by a click pair having an interaural time difference of 400 µs and where the interclick interval was 8.4 ms. The presence of the leading click pair increased the latency of the ABR generated by the lagging diotic click pair but did not decrease its amplitude. The results were interpreted as indicating a contribution of binaural processing at the level of the brainstem to echo suppression, at least for the conditions tested here.


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