Smoking induced alterations in auditory pathways: Evidence from evoked potentials

Objectives: Auditory Brainstem Responses (ABR) are used for assessment of integrity of auditory pathway. Given the widespread prevalence of smoking, interpretation of ABR data must be done in light of smoker/nonsmoker status. Materials and Methods: The present study was done on 30 normal, healthy non-smoker males and 30 healthy, smoker males in the age group of 18-40 years. Approval of Institutional Ethics Committee and written informed consent was taken from all volunteers. ABR was recorded using Biopac MP 150 system. The recordings were done in a state of abstinence of 12 hours (chronic smoking state) and 10 minutes after smoking (acute smoking state). In the non-smoker group, only one set of recordings were done. The peak latencies and amplitudes of the ABR waves were analyzed. Results: Analysis of data revealed a significant prolongation of the latencies of wave I and II and Inter-peak latency I-III in chronic smoking state as compared to non-smoking state. The amplitudes of waves I, II and V were also significantly reduced in chronic smoking state. A comparison between the non-smokers and acute smoking state revealed significantly prolonged latency of waves I and II in the acute smoking state accompanied by a significant decrease in the amplitudes of all waves of ABR. There were no significant differences in latencies and amplitudes of the chronic and acute smoking state. Conclusion: Smoking led to an increase in latency and decrease in amplitude, thereby indicating that it adversely affected the auditory pathway. Thus, interpretation of data of ABR should consider smoking as a confounding variable.

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

BioMed Research International ◽

10.1155/2021/6667531 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Zhe Chen ◽

Yanmei Zhang ◽

Junbo Zhang ◽

Rui Zhou ◽

Zhen Zhong ◽

...

Keyword(s):

Speech Recognition ◽

Action Potential ◽

Animal Studies ◽

Signal To Noise Ratio ◽

Recognition Performance ◽

Auditory Pathway ◽

Auditory Brainstem ◽

Auditory Brainstem Responses ◽

Hearing Ability ◽

Summating Potential

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.

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Vigintiphobia, Unbound Bilirubin, and Auditory Brainstem Responses

PEDIATRICS ◽

10.1542/peds.93.1.50 ◽

1994 ◽

Vol 93 (1) ◽

pp. 50-53 ◽

Cited By ~ 5

Author(s):

Masahisa Funato ◽

Hiroshi Tamai ◽

Seiichi Shimada ◽

Hajime Nakamura

Keyword(s):

Multiple Logistic Regression Analysis ◽

Auditory Brainstem ◽

Auditory Brainstem Responses ◽

Significant Difference ◽

Group A ◽

Term Newborns ◽

Unbound Bilirubin ◽

Group B ◽

Interpeak Latency ◽

Prolonged Latency

Objective. The management of nonhemolytic hyperbilirubinemia in term newborns is controversial. To evaluate the usefulness of serum unbound bilirubin concentrations (UBCs) in the management of hyperbilirubinemia, we compared the concentrations with abnormal auditory brainstem responses (ABRs). Methods. ABRs and serum UBCs in 37 hyperbilirubinemic term newborns (total bilirubin concentrations [TBCs] ≥20 mg/dL and direct bilirubin concentrations <2 mg/dL) were measured before treatment with either phototherapy or exchange transfusions. Eight of these newborns had blood incompatibilities. These hyperbilirubinemic newborns were divided into three groups according to the findings of ABR: group A, normal ABR (n = 18); group B, prolonged latency of wave I only (n = 8); and group C, prolonged interpeak latency of wave I-III/I-V and/or poor amplitude (n = 11). Results. The peak TBC was significantly different between groups A and C (22.8 ± 2.2 mg/dL and 25.4 ± 2.5 mg/dL, respectively; P < .05), though there were no differences between groups A and B and between groups B and C. The peak UBCs in groups B (1.27 ± 0.7 µg/dL) and C (1.34 ± 0.37 µg/dL) were significantly higher than in group A (0.78 ± 0.26 µg/dL) (P < .05 and P < .01, respectively), though there was no significant difference in the peak UBC between groups B and C. Abnormal ABR findings were more clearly associated with the level of UBC at 1.0 µg/dL than that of TBC at 23 mg/dL by multiple logistic regression analysis (odds ratio 16.6, P = .0026, vs 4.2, P = .1272). Conclusions. These results suggest that measuring UBC may help in evaluating the possible risk of bilirubin encephalopathy in full-term newborns when there is vigintiphobia (fear of 20).

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Neural Transformation of Dissonant Intervals in the Auditory Brainstem

Music Perception An Interdisciplinary Journal ◽

10.1525/mp.2015.32.5.445 ◽

2015 ◽

Vol 32 (5) ◽

pp. 445-459 ◽

Cited By ~ 4

Author(s):

Kyung Myun Lee ◽

Erika Skoe ◽

Nina Kraus ◽

Richard Ashley

Keyword(s):

Auditory System ◽

Auditory Processing ◽

Response Spectrum ◽

Phase Locking ◽

Auditory Pathway ◽

Auditory Brainstem ◽

Neural Representation ◽

Auditory Brainstem Responses ◽

Distortion Products ◽

Stimulus Waveform

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.

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Auditory neuropathy in a patient exposed to xylene: case report

The Journal of Laryngology & Otology ◽

10.1017/s0022215108002399 ◽

2008 ◽

Vol 123 (4) ◽

pp. 462-465 ◽

Cited By ~ 4

Author(s):

T H J Draper ◽

D-E Bamiou

Keyword(s):

Case Report ◽

Otoacoustic Emissions ◽

Auditory Pathway ◽

Auditory Brainstem ◽

Auditory Neuropathy ◽

Auditory Brainstem Responses ◽

Test Results ◽

Solvent Exposure ◽

Complex Sounds ◽

Acoustic Reflexes

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.

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Encoding of a binaural speech stimulus at the brainstem level in middle-aged adults

The Journal of Laryngology & Otology ◽

10.1017/s0022215120002285 ◽

2020 ◽

pp. 1-8

Author(s):

A K Neupane ◽

S K Sinha ◽

K Gururaj

Keyword(s):

Binaural Hearing ◽

Auditory Pathway ◽

Auditory Brainstem ◽

Speech Stimulus ◽

Auditory Brainstem Responses ◽

Middle Aged ◽

Fast Fourier Transform Analysis ◽

Significant Difference ◽

Brainstem Response ◽

Middle Aged Adults

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.

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Effects of auditory pathway anatomy and deafness characteristics? (1): On electrically evoked auditory brainstem responses

Hearing Research ◽

10.1016/j.heares.2006.09.014 ◽

2007 ◽

Vol 223 (1-2) ◽

pp. 48-60 ◽

Cited By ~ 5

Author(s):

Jeanne Guiraud ◽

Stéphane Gallego ◽

Laure Arnold ◽

Patrick Boyle ◽

Eric Truy ◽

...

Keyword(s):

Auditory Pathway ◽

Auditory Brainstem ◽

Auditory Brainstem Responses

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Variation in interpeak latencies of auditory brainstem responses with age in male adults:An observation

Biomedicine ◽

10.51248/.v41i2.1064 ◽

2021 ◽

Vol 41 (2) ◽

pp. 489-492

Author(s):

Shilpa Khullar ◽

S. Aijaz Abbas Rizvi ◽

Ankur Sachdeva ◽

Archana Sood ◽

Syed Sibte Akbar Abidi

Keyword(s):

Auditory Processing ◽

Hearing Threshold ◽

Auditory Pathway ◽

Auditory Brainstem ◽

Auditory Threshold ◽

Auditory Brainstem Responses ◽

P Value ◽

Conduction Time ◽

Significant Difference ◽

Group 2

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.

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Auditory Brainstem Response: reference-values for age

CoDAS ◽

10.1590/2317-1782/2014469in ◽

2014 ◽

Vol 26 (2) ◽

pp. 117-121 ◽

Cited By ~ 3

Author(s):

Luana Araujo Cruz Rosa ◽

Marcia Rumi Suzuki ◽

Rosanna Giaffredo Angrisani ◽

Marisa Frassom Azevedo

Keyword(s):

Reference Values ◽

Auditory Brainstem Response ◽

Auditory Brainstem ◽

Auditory Brainstem Responses ◽

Age Group ◽

Group Methods ◽

Brainstem Response ◽

Term Newborns ◽

Absolute Latency ◽

Preterm Newborns

PURPOSE: To study the absolute latencies of waves I , III and V and interpeak I-III , III-V and I-V of Auditory brainstem responses obtained in preterm newborns in relation to post-conceptual age, term newborns and six months of age infants, establishing reference values for each age group. METHODS: Retrospective study realized through the analysis of tests performed on 80 infants divided into four groups, being the group one composed per newborns assessed between 35 and 36 weeks post-conceptual age; group two by newborns assessed between 37 and 38 weeks; group three with newborns reviewed between 39 to 40 weeks; and group four with infants evaluated with six months. RESULTS: The wave I absolute latency in the group one was 1.81 ms, decreasing to 1.79 ms in groups two and three, and to 1.70 ms in group four. The wave III latency in group one was 4.74 ms, decreasing to 4.62 ms in group two, to 4.56 ms in the group three and to 4.37 ms in the group four. The wave V latency in group one was 7.14 ms, in the group two it was 7.05 ms, in the group three 6.90 ms; and in the group four it was 6.50 ms. Interpeak latencies were also decreased in all groups. CONCLUSION: The latencies studied decreased with the increasing age and were similar values with the international literature.

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Neuropatia Auditiva: Avaliação Clínica e Abordagem Diagnóstica

Acta Médica Portuguesa ◽

10.20344/amp.6942 ◽

2016 ◽

Vol 29 (6) ◽

pp. 353 ◽

Cited By ~ 2

Author(s):

Guilherme Machado Carvalho ◽

Beatriz Prista Leão ◽

Priscila Zonzini Ramos ◽

Alexandre Caixeta Guimarães ◽

Arthur Menino Castilho ◽

...

Keyword(s):

Hearing Loss ◽

Case Series ◽

Epidemiological Data ◽

Auditory Pathway ◽

Auditory Brainstem ◽

Auditory Neuropathy ◽

Auditory Brainstem Responses ◽

Profound Deafness ◽

Neuronal Transmission ◽

Patients Experience

Introduction: Auditory neuropathy is a condition in which there is a change in the neuronal transmission of the auditory stimuli. Our objective was to describe the patients’ series within the clinical spectrum of auditory neuropathy. Material and Methods: We designed a transversal, retrospective study, with a description of a consecutive case series. Auditory neuropathy was defined by the presence of acoustic otoemissions plus absent/abnormal auditory brainstem responses with cochlear microphonism. Results: 34 patients with bilateral hearing loss, 23 males and 11 females, were included in the study. Eighty percent of the cases had congenital onset of hearing loss. Acoustic otoemissions were absent in 67% of them. Cochlear microfonism was present in 79% of all cases. Prenatal, perinatal or ambiental factors were present in 35.2% of the cases. Discussion: Medical literature shows great variability in findings related to auditory neuropathy, both in its etiology and epidemiological data. Conclusion: Auditory neuropathy presents a broad spectrum of changes that may result from mild to severe changes in the functioning of the auditory pathway, and in our sample we observed that 80% of Auditory neuropathy have congenital onset of hearing loss and/or with cochlear microphonism identified. 91% of patients experience significant hearing impairment and 53% suffer from severe or profound deafness.

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Electrophysiological assessment and pharmacological treatment of blast-induced tinnitus

PLoS ONE ◽

10.1371/journal.pone.0243903 ◽

2021 ◽

Vol 16 (1) ◽

pp. e0243903

Author(s):

Jianzhong Lu ◽

Matthew B. West ◽

Xiaoping Du ◽

Qunfeng Cai ◽

Donald L. Ewert ◽

...

Keyword(s):

Amplitude Ratio ◽

Expression Patterns ◽

Acoustic Startle ◽

Acoustic Startle Response ◽

Auditory Pathway ◽

Auditory Brainstem ◽

Auditory Brainstem Responses ◽

Significant Treatment ◽

Ribbon Synapses ◽

Behavioral Evidence

Tinnitus, the phantom perception of sound, often occurs as a clinical sequela of auditory traumas. In an effort to develop an objective test and therapeutic approach for tinnitus, the present study was performed in blast-exposed rats and focused on measurements of auditory brainstem responses (ABRs), prepulse inhibition of the acoustic startle response, and presynaptic ribbon densities on cochlear inner hair cells (IHCs). Although the exact mechanism is unknown, the “central gain theory” posits that tinnitus is a perceptual indicator of abnormal increases in the gain (or neural amplification) of the central auditory system to compensate for peripheral loss of sensory input from the cochlea. Our data from vehicle-treated rats supports this rationale; namely, blast-induced cochlear synaptopathy correlated with imbalanced elevations in the ratio of centrally-derived ABR wave V amplitudes to peripherally-derived wave I amplitudes, resulting in behavioral evidence of tinnitus. Logistic regression modeling demonstrated that the ABR wave V/I amplitude ratio served as a reliable metric for objectively identifying tinnitus. Furthermore, histopathological examinations in blast-exposed rats revealed tinnitus-related changes in the expression patterns of key plasticity factors in the central auditory pathway, including chronic loss of Arc/Arg3.1 mobilization. Using a formulation of N-acetylcysteine (NAC) and disodium 2,4-disulfophenyl-N-tert-butylnitrone (HPN-07) as a therapeutic for addressing blast-induced neurodegeneration, we measured a significant treatment effect on preservation or restoration of IHC ribbon synapses, normalization of ABR wave V/I amplitude ratios, and reduced behavioral evidence of tinnitus in blast-exposed rats, all of which accorded with mitigated histopathological evidence of tinnitus-related neuropathy and maladaptive neuroplasticity.

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