scholarly journals Cochlear Synaptopathy: A Primary Factor Affecting Speech Recognition Performance in Presbycusis

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Zhe Chen ◽  
Yanmei Zhang ◽  
Junbo Zhang ◽  
Rui Zhou ◽  
Zhen Zhong ◽  
...  

The results of recent animal studies have suggested that cochlear synaptopathy may be an important factor involved in presbycusis. Therefore, here, we aimed to examine whether cochlear synaptopathy frequently exists in patients with presbycusis and to describe the effect of cochlear synaptopathy on speech recognition in noise. Based on the medical history and an audiological examination, 94 elderly patients with bilateral, symmetrical, sensorineural hearing loss were diagnosed as presbycusis. An electrocochleogram, auditory brainstem responses, auditory cortical evoked potentials, and speech audiometry were recorded to access the function of the auditory pathway. First, 65 ears with hearing levels of 41-50 dB HL were grouped based on the summating potential/action potential (SP/AP) ratio, and the amplitudes of AP and SP were compared between the two resulting groups. Second, 188 ears were divided into two groups: the normal SP/AP and abnormal SP/AP groups. The speech recognition abilities in the two groups were compared. Finally, the relationship between abnormal electrocochleogram and poor speech recognition (signal-to-noise ratio loss ≥7 dB) was analyzed in 188 ears. The results of the present study showed: (1) a remarkable reduction in the action potential amplitude was observed in patients with abnormal SP/AP ratios; this suggests that cochlear synaptopathy was involved in presbycusis. (2) There was a large proportion of patients with poor speech recognition in the abnormal SP/AP group. Furthermore, a larger number of cases with abnormal SP/AP ratios were confirmed among patients with presbycusis and poor speech recognition. We concluded that cochlear synaptopathy is not uncommon among elderly individuals who have hearing ability deficits, and it may have a more pronounced effect on ears with declining auditory performance in noisy environments.

2020 ◽  
Vol 63 (11) ◽  
pp. 3877-3892
Author(s):  
Ashley Parker ◽  
Candace Slack ◽  
Erika Skoe

Purpose Miniaturization of digital technologies has created new opportunities for remote health care and neuroscientific fieldwork. The current study assesses comparisons between in-home auditory brainstem response (ABR) recordings and recordings obtained in a traditional lab setting. Method Click-evoked and speech-evoked ABRs were recorded in 12 normal-hearing, young adult participants over three test sessions in (a) a shielded sound booth within a research lab, (b) a simulated home environment, and (c) the research lab once more. The same single-family house was used for all home testing. Results Analyses of ABR latencies, a common clinical metric, showed high repeatability between the home and lab environments across both the click-evoked and speech-evoked ABRs. Like ABR latencies, response consistency and signal-to-noise ratio (SNR) were robust both in the lab and in the home and did not show significant differences between locations, although variability between the home and lab was higher than latencies, with two participants influencing this lower repeatability between locations. Response consistency and SNR also patterned together, with a trend for higher SNRs to pair with more consistent responses in both the home and lab environments. Conclusions Our findings demonstrate the feasibility of obtaining high-quality ABR recordings within a simulated home environment that closely approximate those recorded in a more traditional recording environment. This line of work may open doors to greater accessibility to underserved clinical and research populations.


2015 ◽  
Vol 32 (5) ◽  
pp. 445-459 ◽  
Author(s):  
Kyung Myun Lee ◽  
Erika Skoe ◽  
Nina Kraus ◽  
Richard Ashley

Acoustic periodicity is an important factor for discriminating consonant and dissonant intervals. While previous studies have found that the periodicity of musical intervals is temporally encoded by neural phase locking throughout the auditory system, how the nonlinearities of the auditory pathway influence the encoding of periodicity and how this effect is related to sensory consonance has been underexplored. By measuring human auditory brainstem responses (ABRs) to four diotically presented musical intervals with increasing degrees of dissonance, this study seeks to explicate how the subcortical auditory system transforms the neural representation of acoustic periodicity for consonant versus dissonant intervals. ABRs faithfully reflect neural activity in the brainstem synchronized to the stimulus while also capturing nonlinear aspects of auditory processing. Results show that for the most dissonant interval, which has a less periodic stimulus waveform than the most consonant interval, the aperiodicity of the stimulus is intensified in the subcortical response. The decreased periodicity of dissonant intervals is related to a larger number of nonlinearities (i.e., distortion products) in the response spectrum. Our findings suggest that the auditory system transforms the periodicity of dissonant intervals resulting in consonant and dissonant intervals becoming more distinct in the neural code than if they were to be processed by a linear auditory system.


2003 ◽  
Vol 12 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Paula Henry ◽  
Todd Ricketts

Improving the signal-to-noise ratio (SNR) for individuals with hearing loss who are listening to speech in noise provides an obvious benefit. Although binaural hearing provides the greatest advantage over monaural hearing in noise, some individuals with symmetrical hearing loss choose to wear only one hearing aid. The present study tested the hypothesis that individuals with symmetrical hearing loss fit with one hearing aid would demonstrate improved speech recognition in background noise with increases in head turn. Fourteen individuals were fit monaurally with a Starkey Gemini in-the-ear (ITE) hearing aid with directional and omnidirectional microphone modes. Speech recognition performance in noise was tested using the audiovisual version of the Connected Speech Test (CST v.3). The test was administered in auditory-only conditions as well as with the addition of visual cues for each of three head angles: 0°, 20°, and 40°. Results indicated improvement in speech recognition performance with changes in head angle for the auditory-only presentation mode at the 20° and 40° head angles when compared to 0°. Improvement in speech recognition performance for the auditory + visual mode was noted for the 20° head angle when compared to 0°. Additionally, a decrement in speech recognition performance for the auditory + visual mode was noted for the 40° head angle when compared to 0°. These results support a speech recognition advantage for listeners fit with one ITE hearing aid listening in a close listener-to-speaker distance when they turn their head slightly in order to increase signal intensity.


2008 ◽  
Vol 123 (4) ◽  
pp. 462-465 ◽  
Author(s):  
T H J Draper ◽  
D-E Bamiou

AbstractObjective:To report the case of an adult patient who developed auditory complaints following xylene exposure, and to review the literature on the effects of solvent exposure on hearing.Case report:The patient presented with a gradual deterioration in his ability to hear in difficult acoustic environments and also to hear complex sounds such as music, over a 40-year period. His symptoms began following exposure to the solvent xylene, and in the absence of any other risk factor. Our audiological investigations revealed normal otoacoustic emissions with absent auditory brainstem responses and absent acoustic reflexes in both ears, consistent with a diagnosis of bilateral auditory neuropathy. Central test results were also abnormal, indicating possible involvement of the central auditory pathway.Conclusions:To our knowledge, this is the first report of retrocochlear hearing loss following xylene exposure. The test results may provide some insight into the effect of xylene as an isolated agent on the human auditory pathway.


Author(s):  
A K Neupane ◽  
S K Sinha ◽  
K Gururaj

Abstract Objective Binaural hearing is facilitated by neural interactions in the auditory pathway. Ageing results in impairment of localisation and listening in noisy situations without any significant hearing loss. The present study focused on comparing the binaural encoding of a speech stimulus at the subcortical level in middle-aged versus younger adults, based on speech-evoked auditory brainstem responses. Methods Thirty participants (15 young adults and 15 middle-aged adults) with normal hearing sensitivity (less than 15 dB HL) participated in the study. The speech-evoked auditory brainstem response was recorded monaurally and binaurally with a 40-ms /da/ stimulus. Fast Fourier transform analysis was utilised. Results An independent sample t-test revealed a significant difference between the two groups in fundamental frequency (F0) amplitude recorded with binaural stimulation. Conclusion The present study suggested that ageing results in degradation of F0 encoding, which is essential for the perception of speech in noise.


2007 ◽  
Vol 223 (1-2) ◽  
pp. 48-60 ◽  
Author(s):  
Jeanne Guiraud ◽  
Stéphane Gallego ◽  
Laure Arnold ◽  
Patrick Boyle ◽  
Eric Truy ◽  
...  

Biomedicine ◽  
2021 ◽  
Vol 41 (2) ◽  
pp. 489-492
Author(s):  
Shilpa Khullar ◽  
S. Aijaz Abbas Rizvi ◽  
Ankur Sachdeva ◽  
Archana Sood ◽  
Syed Sibte Akbar Abidi

Introduction and Aim: Aging of the auditory pathway is a complex phenomenon consisting of changes in the auditory processing along with a significant elevation of the hearing threshold. The aim of our study was to see the variation in interpeak latencies (IPLs) of Auditory Brainstem Responses (ABRs) with advancing age in males.   Materials and Methods: It was an observational study conducted on 60 Indian male subjects aged between 20 and 80 years divided into three groups on the basis of age: Group 1: 20-40 years, Group 2: 41-60 years and Group 3: 61-80 years. Auditory threshold and ABRs were recorded and analysed for interpeak latencies (IPLs) – I-III,I-V and III-V in msec.The comparison of data between the groups was done using one – way ANOVA and Tukey Kramer multiple comparison test. The results were considered significantly different between the groups when ‘P value’ was ? 0.05.   Results: It was found that there was no significant difference in the auditory threshold and interpeak latencies (IPLs) when comparison was made between the three groups.   Conclusion: Hence we conclude thatage does not have any significant influence on neural conduction time of the auditory pathway which is represented by the IPLs in ABRs.  


2021 ◽  
Vol 15 ◽  
Author(s):  
Florine L. Bachmann ◽  
Ewen N. MacDonald ◽  
Jens Hjortkjær

Linearized encoding models are increasingly employed to model cortical responses to running speech. Recent extensions to subcortical responses suggest clinical perspectives, potentially complementing auditory brainstem responses (ABRs) or frequency-following responses (FFRs) that are current clinical standards. However, while it is well-known that the auditory brainstem responds both to transient amplitude variations and the stimulus periodicity that gives rise to pitch, these features co-vary in running speech. Here, we discuss challenges in disentangling the features that drive the subcortical response to running speech. Cortical and subcortical electroencephalographic (EEG) responses to running speech from 19 normal-hearing listeners (12 female) were analyzed. Using forward regression models, we confirm that responses to the rectified broadband speech signal yield temporal response functions consistent with wave V of the ABR, as shown in previous work. Peak latency and amplitude of the speech-evoked brainstem response were correlated with standard click-evoked ABRs recorded at the vertex electrode (Cz). Similar responses could be obtained using the fundamental frequency (F0) of the speech signal as model predictor. However, simulations indicated that dissociating responses to temporal fine structure at the F0 from broadband amplitude variations is not possible given the high co-variance of the features and the poor signal-to-noise ratio (SNR) of subcortical EEG responses. In cortex, both simulations and data replicated previous findings indicating that envelope tracking on frontal electrodes can be dissociated from responses to slow variations in F0 (relative pitch). Yet, no association between subcortical F0-tracking and cortical responses to relative pitch could be detected. These results indicate that while subcortical speech responses are comparable to click-evoked ABRs, dissociating pitch-related processing in the auditory brainstem may be challenging with natural speech stimuli.


2014 ◽  
Vol 25 (06) ◽  
pp. 529-540 ◽  
Author(s):  
Erin C. Schafer ◽  
Danielle Bryant ◽  
Katie Sanders ◽  
Nicole Baldus ◽  
Katherine Algier ◽  
...  

Background: Several recent investigations support the use of frequency modulation (FM) systems in children with normal hearing and auditory processing or listening disorders such as those diagnosed with auditory processing disorders, autism spectrum disorders, attention-deficit hyperactivity disorder, Friedreich ataxia, and dyslexia. The American Academy of Audiology (AAA) published suggested procedures, but these guidelines do not cite research evidence to support the validity of the recommended procedures for fitting and verifying nonoccluding open-ear FM systems on children with normal hearing. Documenting the validity of these fitting procedures is critical to maximize the potential FM-system benefit in the abovementioned populations of children with normal hearing and those with auditory-listening problems. Purpose: The primary goal of this investigation was to determine the validity of the AAA real-ear approach to fitting FM systems on children with normal hearing. The secondary goal of this study was to examine speech-recognition performance in noise and loudness ratings without and with FM systems in children with normal hearing sensitivity. Research Design: A two-group, cross-sectional design was used in the present study. Study Sample: Twenty-six typically functioning children, ages 5–12 yr, with normal hearing sensitivity participated in the study. Intervention: Participants used a nonoccluding open-ear FM receiver during laboratory-based testing. Data Collection and Analysis: Participants completed three laboratory tests: (1) real-ear measures, (2) speech recognition performance in noise, and (3) loudness ratings. Four real-ear measures were conducted to (1) verify that measured output met prescribed-gain targets across the 1000–4000 Hz frequency range for speech stimuli, (2) confirm that the FM-receiver volume did not exceed predicted uncomfortable loudness levels, and (3 and 4) measure changes to the real-ear unaided response when placing the FM receiver in the child’s ear. After completion of the fitting, speech recognition in noise at a –5 signal-to-noise ratio and loudness ratings at a +5 signal-to-noise ratio were measured in four conditions: (1) no FM system, (2) FM receiver on the right ear, (3) FM receiver on the left ear, and (4) bilateral FM system. Results: The results of this study suggested that the slightly modified AAA real-ear measurement procedures resulted in a valid fitting of one FM system on children with normal hearing. On average, prescriptive targets were met for 1000, 2000, 3000, and 4000 Hz within 3 dB, and maximum output of the FM system never exceeded and was significantly lower than predicted uncomfortable loudness levels for the children. There was a minimal change in the real-ear unaided response when the open-ear FM receiver was placed into the ear. Use of the FM system on one or both ears resulted in significantly better speech recognition in noise relative to a no-FM condition, and the unilateral and bilateral FM receivers resulted in a comfortably loud signal when listening in background noise. Conclusions: Real-ear measures are critical for obtaining an appropriate fit of an FM system on children with normal hearing.


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