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The Journal of the Acoustical Society... Apr 2023The auditory nerve (AN) compound action potential (CAP) is an important tool for assessing auditory disorders and monitoring the health of the auditory periphery during...
The auditory nerve (AN) compound action potential (CAP) is an important tool for assessing auditory disorders and monitoring the health of the auditory periphery during surgical procedures. The CAP has been mathematically conceptualized as the convolution of a unit response (UR) waveform with the firing rate of a population of AN fibers. Here, an approach for predicting experimentally recorded CAPs in humans is proposed, which involves the use of human-based computational models to simulate AN activity. CAPs elicited by clicks, chirps, and amplitude-modulated carriers were simulated and compared with empirically recorded CAPs from human subjects. In addition, narrowband CAPs derived from noise-masked clicks and tone bursts were simulated. Many morphological, temporal, and spectral aspects of human CAPs were captured by the simulations for all stimuli tested. These findings support the use of model simulations of the human CAP to refine existing human-based models of the auditory periphery, aid in the design and analysis of auditory experiments, and predict the effects of hearing loss, synaptopathy, and other auditory disorders on the human CAP.
Topics: Humans; Action Potentials; Acoustic Stimulation; Noise; Hearing Loss; Computer Simulation; Cochlear Nerve; Auditory Threshold; Cochlea
PubMed: 37092943
DOI: 10.1121/10.0017863 -
Journal of Otolaryngology - Head & Neck... Mar 2016The Canadian Hearing and Auditory Research Translation (CHART) group is a newly formed taskforce to develop collaborative research initiatives. Initial discussions...
The Canadian Hearing and Auditory Research Translation (CHART) group is a newly formed taskforce to develop collaborative research initiatives. Initial discussions centered on diagnostic improvements for middle ear disease, auditory neuropathy spectrum disorder, tinnitus and presbycusis. Central to these discussions was the widely held view that the standard audiogram and its interpretation is inadequate to for describing many forms of hearing problems that we now recognize. This letter is designed to create awareness and to seek feedback from hearing healthcare professionals on their experience regarding the adequacy (or otherwise) of the audiogram in its present form.
Topics: Audiometry, Pure-Tone; Auditory Threshold; Canada; Hearing Loss; Humans
PubMed: 26965445
DOI: 10.1186/s40463-016-0132-8 -
The Journal of the Acoustical Society... Dec 2021Although clinical use of the auditory brainstem response (ABR) to detect retrocochlear disorders has been largely replaced by imaging in recent years, the discovery of... (Review)
Review
Although clinical use of the auditory brainstem response (ABR) to detect retrocochlear disorders has been largely replaced by imaging in recent years, the discovery of cochlear synaptopathy has thrown this foundational measure of auditory function back into the spotlight. Whereas modern imaging now allows for the noninvasive detection of vestibular schwannomas, imaging technology is not currently capable of detecting cochlear synaptopathy, the loss of the synaptic connections between the inner hair cells and afferent auditory nerve fibers. However, animal models indicate that the amplitude of the first wave of the ABR, a far-field evoked potential generated by the synchronous firing of auditory nerve fibers, is highly correlated with synaptic integrity. This has led to many studies investigating the use of the ABR as a metric of synaptopathy in humans. However, these studies have yielded mixed results, leading to a lack of consensus about the utility of the ABR as an indicator of synaptopathy. This review summarizes the animal and human studies that have investigated the ABR as a measure of cochlear synaptic function, discusses factors that may have contributed to the mixed findings and the lessons learned, and provides recommendations for future use of this metric in the research and clinical settings.
Topics: Animals; Auditory Threshold; Cochlea; Cochlear Nerve; Evoked Potentials, Auditory, Brain Stem; Hearing Loss, Noise-Induced; Humans; Noise
PubMed: 34972291
DOI: 10.1121/10.0007484 -
Age-related Changes in Neural Coding of Envelope Cues: Peripheral Declines and Central Compensation.Neuroscience May 2019Aging listeners often experience difficulties in perceiving temporally complex acoustic cues in noisy environments. These difficulties likely have neurophysiological... (Review)
Review
Aging listeners often experience difficulties in perceiving temporally complex acoustic cues in noisy environments. These difficulties likely have neurophysiological contributors from various levels of auditory processing. Cochlear synapses between inner hair cells and auditory nerve fibers exhibit a progressive decline with age which is not reflected in the threshold audiogram. The functional consequences of this loss for the coding of suprathreshold sound remain poorly understood. Recent studies suggest that cochlear synaptopathy results in degraded representations of temporal envelope cues at the earliest levels of the auditory pathway. Central nuclei downstream of the auditory nerve exhibit a compensatory plasticity in response to this deafferentation, in the form of altered gain. This results in a modulation frequency selective increase in the representation of envelope cues at the level of the auditory midbrain and cortex. These changes may be shaped by mechanisms such as decreased inhibitory neurotransmission occurring with age across various central auditory nuclei. Altered representations of the differing temporal components of speech due to these interactions between multiple levels of the auditory pathway may contribute to the age-related difficulties hearing speech in noisy environments.
Topics: Aging; Animals; Auditory Perception; Auditory Threshold; Cochlear Nerve; Evoked Potentials, Auditory, Brain Stem; Hearing; Hearing Loss, Noise-Induced; Humans
PubMed: 30553793
DOI: 10.1016/j.neuroscience.2018.12.007 -
Hearing Research Apr 2022There is a large amount of variability in performance in masked-speech reception tasks, as well as in psychophysical auditory temporal processing tasks, between...
There is a large amount of variability in performance in masked-speech reception tasks, as well as in psychophysical auditory temporal processing tasks, between listeners with normal or relatively normal low-frequency hearing. In this study we used a cross-sectional dataset collected on 102 listeners (34 young, 34 middle-aged, 34 older) to assess whether variance in these tasks could be explained by variance in subcortical electrophysiological measures of auditory function (auditory brainstem responses and frequency following responses), and whether variance in speech-reception performance could be explained by variance in auditory temporal processing tasks. The potential confounding effect of high-frequency sensitivity was strictly controlled for by using highpass masking noise. Because each high-level construct (masked-speech reception, auditory temporal processing, and subcortical electrophysiological function) was indexed by several variables, we used principal component analyses to reduce the dimensionality of the dataset. Multiple-regression models were then used to assess the associations between the extracted principal components while controlling for a range of possible confounders including age and audiometric thresholds. We found that masked-speech reception was credibly associated with psychophysical auditory temporal processing abilities. No credible associations were found between masked-speech reception and electrophysiological measures of subcortical auditory function, or between psychophysical measures of auditory temporal processing and electrophysiological measures of subcortical auditory function. These results suggest that either the electrophysiological measures of subcortical auditory function used were not sufficiently sensitive to the subcortical neural processes limiting performance in the speech-reception and psychophysical auditory temporal-processing tasks, or that variance in these tasks is largely unrelated to variance in subcortical neural processes in listeners with near-normal hearing.
Topics: Auditory Threshold; Cross-Sectional Studies; Hearing; Humans; Middle Aged; Perceptual Masking; Speech; Speech Perception; Time Perception
PubMed: 35149333
DOI: 10.1016/j.heares.2022.108456 -
International Journal of Molecular... Jul 2023The auditory brainstem response (ABR) is a scalp recording of potentials produced by sound stimulation, and is commonly used as an indicator of auditory function....
The auditory brainstem response (ABR) is a scalp recording of potentials produced by sound stimulation, and is commonly used as an indicator of auditory function. However, the ABR threshold, which is the lowest audible sound pressure, cannot be objectively determined since it is determined visually using a measurer, and this has been a problem for several decades. Although various algorithms have been developed to objectively determine ABR thresholds, they remain lacking in terms of accuracy, efficiency, and convenience. Accordingly, we proposed an improved algorithm based on the mutual covariance at adjacent sound pressure levels. An ideal ABR waveform with clearly defined waves I-V was created; moreover, using this waveform as a standard template, the experimentally obtained ABR waveform was inspected for disturbances based on mutual covariance. The ABR testing was repeated if the value was below the established cross-covariance reference value. Our proposed method allowed more efficient objective determination of ABR thresholds and a smaller burden on experimental animals.
Topics: Mice; Animals; Evoked Potentials, Auditory, Brain Stem; Acoustic Stimulation; Auditory Threshold; Hearing; Disease Models, Animal
PubMed: 37511152
DOI: 10.3390/ijms241411393 -
Journal of Speech, Language, and... Oct 2019Purpose Spectral modulation detection is an increasingly common assay of suprathreshold auditory perception and has been correlated with speech perception performance.... (Randomized Controlled Trial)
Randomized Controlled Trial
Purpose Spectral modulation detection is an increasingly common assay of suprathreshold auditory perception and has been correlated with speech perception performance. Here, the potential effects of stimulus duration and stimulus presentation level on spectral modulation detection were investigated. Method Spectral modulation detection thresholds were measured as a function of modulation frequency in young, normal-hearing listeners. The standard stimulus was a bandpass noise, and signal stimuli were created by superimposing sinusoidal spectral modulation on the bandpass noise carrier. The modulation was sinusoidal on a log frequency axis and a log (dB) amplitude scale with a random starting phase (0-2π radians). In 1 experiment, stimulus durations were 50, 100, 200, or 400 ms (at fixed level 81 dB SPL). In a 2nd experiment, stimuli were presented at sensation levels of 10, 20, 30, 40, and 60 dB SL (fixed at a duration of 400 ms). Results Spectral modulation detection thresholds were similarly low for the 400- and 200-ms durations, increased slightly for the 100-ms duration, and increased markedly for the 50-ms duration. Thresholds were lowest for 40 dB SL; increased slightly for 20, 30, and 60 dB SL; and markedly higher for the 10-dB SL condition. Conclusions The increase in thresholds for the shortest durations and lowest sensational levels is consistent with previous investigations of auditory spectral profile analysis. The effects of presentation level and stimulus duration are important considerations in the context of understanding potential relationships between the perception of spectral cues and speech perception, when designing investigations and interpreting data related to spectral envelope perception, and in the context of models of auditory perception. As examples, 2 simple models based on auditory nerve output that have been used to explain spectrotemporal modulation in previous investigations produced an output inconsistent with the present results. Plain language summary Intensity variations across audio frequency lead to spectral shapes that are essential and sometimes signature features of various sounds in the environment, including speech. Here, we show how laboratory measures of spectral shape perception depend on presentation level and stimulus duration.
Topics: Acoustic Stimulation; Adult; Auditory Perception; Auditory Threshold; Female; Healthy Volunteers; Hearing; Humans; Male; Noise; Speech Perception; Time Factors; Young Adult
PubMed: 31638883
DOI: 10.1044/2019_JSLHR-H-18-0449 -
CoDAS 2023To investigate the functionalities of the neural pathways through the auditory evoked potentials of the brainstem and the contralateral stapedial acoustic reflexes in...
PURPOSE
To investigate the functionalities of the neural pathways through the auditory evoked potentials of the brainstem and the contralateral stapedial acoustic reflexes in normal-hearing individuals with type 1 diabetes mellitus, in order to detect possible alterations in the central auditory pathways.
METHODS
This is a cross-sectional study with a comparison group and a convenience sample, consisting of 32 individuals with type 1 diabetes mellitus and 20 controls without the disease. All subjects had hearing thresholds within normal limits and type A tympanometric curves. The acoustic reflex arc and brainstem auditory potentials were investigated. Statistical analyses were performed using the SPSS 17.0. The Chi-square test, Student´s t-test, and Multiple linear regression were used.
RESULTS
The auditory thresholds of the acoustic reflex were statistically lower in the group with the disease at frequencies of 0.5 kHz and 1.0 kHz in the left ear (p=0.01 and p=0.01, respectively). The absolute latencies III and V of the auditory potentials of the brainstem in the right ear and V in the left ear were increased in subjects with type 1 diabetes mellitus (p=0.03, p=0.02 and p=0.03, respectively).
CONCLUSION
The findings suggest that subjects with type 1 diabetes mellitus are more likely to present alterations in the central auditory pathways, even with auditory thresholds within normal limits.
Topics: Humans; Evoked Potentials, Auditory, Brain Stem; Reflex, Acoustic; Auditory Pathways; Diabetes Mellitus, Type 1; Cross-Sectional Studies; Evoked Potentials, Auditory; Acoustic Impedance Tests; Auditory Threshold
PubMed: 37194912
DOI: 10.1590/2317-1782/20232021022 -
Journal of the Association For Research... Dec 2022The middle-ear system relies on a balance of mass and stiffness characteristics for transmitting sound from the external environment to the cochlea and auditory neural...
The middle-ear system relies on a balance of mass and stiffness characteristics for transmitting sound from the external environment to the cochlea and auditory neural pathway. Phase is one aspect of sound that, when transmitted and encoded by both ears, contributes to binaural cue sensitivity and spatial hearing. The study aims were (i) to investigate the effects of middle-ear stiffness on the auditory brainstem neural encoding of phase in human adults with normal pure-tone thresholds and (ii) to investigate the relationships between middle-ear stiffness-induced changes in wideband acoustic immittance and neural encoding of phase. The auditory brainstem neural encoding of phase was measured using the auditory steady-state response (ASSR) with and without middle-ear stiffness elicited via contralateral activation of the middle-ear muscle reflex (MEMR). Middle-ear stiffness was quantified using a wideband acoustic immittance assay of acoustic absorbance. Statistical analyses demonstrated decreased ASSR phase lag and decreased acoustic absorbance with contralateral activation of the MEMR, consistent with increased middle-ear stiffness changing the auditory brainstem neural encoding of phase. There were no statistically significant correlations between stiffness-induced changes in wideband acoustic absorbance and ASSR phase. The findings of this study may have important implications for understanding binaural cue sensitivity and horizontal plane sound localization in audiologic and otologic clinical populations that demonstrate changes in middle-ear stiffness, including cochlear implant recipients who use combined electric and binaural acoustic hearing and otosclerosis patients.
Topics: Adult; Humans; Ear, Middle; Hearing Tests; Hearing; Cochlear Nerve; Brain Stem; Auditory Threshold; Acoustic Stimulation
PubMed: 36214911
DOI: 10.1007/s10162-022-00872-0 -
Fa Yi Xue Za Zhi Feb 2024To study the application of CE-Chirp in the evaluation of hearing impairment in forensic medicine by testing the auditory brainstem response (ABR) in adults using...
OBJECTIVES
To study the application of CE-Chirp in the evaluation of hearing impairment in forensic medicine by testing the auditory brainstem response (ABR) in adults using CE-Chirp to analyze the relationship between the V-wave response threshold of CE-Chirp ABR test and the pure tone hearing threshold.
METHODS
Subjects (aged 20-77 with a total of 100 ears) who underwent CE-Chirp ABR test in Changzhou De'an Hospital from January 2018 to June 2019 were selected to obtain the V-wave response threshold, and pure tone air conduction hearing threshold tests were conducted at 0.5, 1.0, 2.0 and 4.0 kHz, respectively, to obtain pure tone listening threshold. The differences and statistical differences between the average pure tone hearing threshold and V-wave response threshold were compared in different hearing levels and different age groups. The correlation, differences and statistical differences between the two tests at each frequency were analyzed for all subjects. The linear regression equation for estimating pure tone hearing threshold for all subjects CE-Chirp ABR V-wave response threshold was established, and the feasibility of the equation was tested.
RESULTS
There was no statistical significance in the CE-Chirp ABR response threshold and pure tone hearing threshold difference between different hearing level groups and different age groups (0.05). There was a good correlation between adult CE-Chirp ABR V-wave response threshold and pure tone hearing threshold with statistical significance (<0.05), and linear regression analysis showed a significant linear correlation between the two (<0.05).
CONCLUSIONS
The use of CE-Chirp ABR V-wave response threshold can be used to evaluate subjects' pure tone hearing threshold under certain conditions, and can be used as an audiological test method for forensic hearing impairment assessment.
Topics: Adult; Humans; Acoustic Stimulation; Auditory Threshold; Hearing; Hearing Loss; Audiometry, Pure-Tone; Evoked Potentials, Auditory, Brain Stem
PubMed: 38500456
DOI: 10.12116/j.issn.1004-5619.2021.210101