Animals ; Auditory Threshold ; Cochlea ; physiology ; Ear, Middle ; surgery ; Evoked Potentials, Auditory, Brain Stem ; Female ; Male ; Rats

OBJECTIVE: To investigate the auditory characteristics of guinea pigs immunized with purified P0 protein from inner ear of guinea pigs. METHOD: Purified inner ear P0 protein was made by Preparative SDS-PAGE. To evaluate the results of Auditory Brainstem Response (ABR), Compound Action Potention (CAP), and Distortion Product Oto-acoustic Emissions (DPOAE) in guinea pigs immunized with purified guinea pigs inner ear myelin protein P0. RESULT: Seven ears of the guinea pigs immunized with purified inner ear P0 protein developed hearing loss. In the ABR study, peak latencies of wave I, III and the interpeak latency of I -III, I-IV were elevated in this group of guinea pigs compared with the control group (P < 0.01). But the interpeak latency of III-IV did not change. In the CAP study, the threshold elevated and latency prolonged (P < 0.01). No significant change of DPOAE was found in the P0-sensitized guinea pigs when compared to controls (P > 0.05). Even though the contra-lateral suppressive effect had the depressed tendency, but there was no significant different when compared with the controls (P > 0.05). CONCLUSION Purified inner ear P0 protein is an important autoimmune inner ear antigen and can develop autoimmune disease of the auditory nerve.
Animals ; Auditory Threshold ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Guinea Pigs ; Immunization ; Myelin P0 Protein ; immunology

BACKGROUNDThe auditory brainstem implants (ABIs) have been used to treat deafness for patients with neurofibromatosis Type 2 and nontumor patients. The lack of an appropriate animal model has limited the study of improving hearing rehabilitation by the device. This study aimed to establish an animal model of ABI in adult rhesus macaque monkey (Macaca mulatta).

METHODSSix adult rhesus macaque monkeys (M. mulatta) were included. Under general anesthesia, a multichannel ABI was implanted into the lateral recess of the fourth ventricle through the modified suboccipital-retrosigmoid (RS) approach. The electrical auditory brainstem response (EABR) waves were tested to ensure the optimal implant site. After the operation, the EABR and computed tomography (CT) were used to test and verify the effectiveness via electrophysiology and anatomy, respectively. The subjects underwent behavioral observation for 6 months, and the postoperative EABR was tested every two weeks from the 1 st month after implant surgery.

RESULTThe implant surgery lasted an average of 5.2 h, and no monkey died or sacrificed. The averaged latencies of peaks I, II and IV were 1.27, 2.34 and 3.98 ms, respectively in the ABR. One-peak EABR wave was elicited in the operation, and one- or two-peak waves were elicited during the postoperative period. The EABR wave latencies appeared to be constant under different stimulus intensities; however, the amplitudes increased as the stimulus increased within a certain scope.

CONCLUSIONSIt is feasible and safe to implant ABIs in rhesus macaque monkeys (M. mulatta) through a modified suboccipital RS approach, and EABR and CT are valid tools for animal model establishment. In addition, this model should be an appropriate animal model for the electrophysiological and behavioral study of rhesus macaque monkey with ABI.

Animals ; Auditory Brain Stem Implants ; Deafness ; surgery ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Female ; Macaca mulatta ; Male

OBJECTIVES: To explore the characters and the relationship among latency response, amplitude and sound stimulus intensity of auditory long latency response（ALR）, and to investigate the significance of ALR applied in auditory threshold prediction. METHODS: Total 46 subjects （92 ears） with normal hearing were tested by ALR. The ALR waves of the subjects were elicited by 5 sound stimulus intensity according to the order of 70, 50, 30, 20 and 10 dB nHL. By making N₁ wave and P₂ wave, the values of 3 observed indexes （the latencies of N₁ wave and P₂ wave and N₁-P₂ amplitude） were obtained, and the variation trend of the observed indexes were statistically analyzed. The differences in the frequency of the indexes were observed. RESULTS: The rate of ALR waves from 46 subjects （92 ears） with normal hearing was 100%. The latencies of N₁ wave and P₂ wave delayed gradually and N₁-P₂ amplitude declined with sound stimulus intensity descending. CONCLUSIONS In suitable conditions, ALR is a stable technology for hearing thresholds prediction. The relation between sound stimulus intensity and latency of N₁ wave, latency of P₂ wave and N₁-P₂ amplitude of ALR plays an important part in auditory thresholds assessment.
Acoustic Stimulation ; Auditory Threshold/physiology* ; Evoked Potentials, Auditory ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Female ; Hearing ; Humans ; Male ; Noise ; Reaction Time

In addition to aberrant features in the speech, children with Autism Spectrum Disorder (ASD) may present unusual responses to sensory stimuli, especially to auditory stimuli. We investigated the auditory ability of children with ASD by using Auditory Brainstem Responses (ABR) as they can directly judge both hearing status and the integrity of auditory brainstem pathways. One hundred twenty-one children (71: ASD; M 58/ F 13, mean age; 41.8 months, 50: control group; M 41/ F 9, mean age; 38 months) were induded in the study. As compared with the values in the control group, the latency of wave V, wave I-V, and wave III-V inter-peak latencies were significantly prolonged (p<0.05) in the ASD group. The findings indicate that children with ASD have a dysfunction or immaturity of the central auditory nervous system. We suggest any children with prolonged III-V inter-peak latencies, especially high functioning children should be further evaluated for central auditory processing to set up a more appropriate treatment plan.
Analysis of Variance ; Auditory Pathways/physiopathology ; Autistic Disorder/*physiopathology ; Child, Preschool ; Electrophysiology ; Evoked Potentials, Auditory, Brain Stem/*physiology ; Female ; Humans ; Male

OBJECTIVES: To explore the relationship between the frequency characteristics and response threshold of auditory steady-state response (ASSR), auditory brainstem response (ABR) and 40 Hz auditory event related potential (40 Hz AERP), and their application values in forensic medicine. METHODS: Thirty volunteers with normal hearing (60 ears) were selected to perform pure tone audiometry (PTA) threshold and ASSR, ABR and 40 Hz AERP response threshold tests in the standard sound insulation shielding room, and the results were statistically analyzed by SPSS 22.0 software. RESULTS: At 0.5 kHz and 1.0 kHz frequencies, the correlation between 40 Hz AERP response threshold and PTA threshold was good, which was better than that of ASSR and ABR response threshold. At 2.0 kHz and 4.0 kHz frequencies, the correlation between ASSR and ABR response thresholds and PTA threshold was good, which was better than that of 40 Hz AERP response threshold. CONCLUSIONS To evaluate the hearing at 0.5 kHz and 1.0 kHz frequencies, it is recommended to use 40 Hz AERP and ASSR to comprehensively assess the PTA threshold of the subjects. To evaluate the hearing at 2.0 kHz and 4.0 kHz frequencies, ABR and ASSR are recommended to assess the PTA threshold of subjects comprehensively. The combination of ASSR, ABR and 40 Hz AERP can improve the accuracy of hearing function evaluation.
Acoustic Stimulation/methods* ; Audiometry, Evoked Response ; Audiometry, Pure-Tone ; Auditory Threshold/physiology* ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Forensic Medicine ; Hearing/physiology* ; Humans

In some auditory evoked potential (AEP) examinations, high rate stimulation paradigms deliver more stimuli with the same period of time, which might lead to overlapping responses. At present, several established techniques can be proposed to address such problem, thus the research scope in both scientific and clinical applications is expanded. In this study, the restoring efficiency of evoked responses is investigated using a simulation strategy. We examined the AEPs derived from three paradigms--conventional ensemble averaging, continuous loop averaging deconvolution (CLAD) and maximum length sequence (MLS). Their performances were evaluated by correlation coefficients and Euclidean distances between ideal and the derived responses. We found that MLS can only slightly enhance the performance at the cost of larger stimulus jitter and much more stimulus numbers; while CLAD method with lower jittering even degenerates the quality, suggesting that, in practical use, the recording efficiency will not be significantly improved by simply using high rate stimulation with overlapping responses introduced.
Acoustic Stimulation ; Algorithms ; Artifacts ; Electroencephalography ; methods ; Evoked Potentials, Auditory ; physiology ; Evoked Potentials, Auditory, Brain Stem ; Humans ; Models, Theoretical ; Signal Processing, Computer-Assisted

OBJECTIVE: To provide supports for the application of auditory evoked potential (AEP) in the evaluation of behavioral threshold, by studying the difference and relevance between the pure tone audiometry (PTA) and three frequency-specific auditory evoked potentials, including 40 Hz auditory event related potentials (40 Hz AERP), tone burst auditory brainstem response (Tb-ABR) and auditory steady-state response (ASSR). METHODS: Three frequency-specific AEP and PTA thresholds were recorded at speech frequency (0.5, 1, 2, 4 kHz) from thirty-four adults with normal hearing (68 ears). Then, the relationship between the AEP thresholds and PTA thresholds were analyzed respectively. RESULTS: There were good correlations between three frequency-specific AEP thresholds and PTA thresholds at speech frequency. However, the difference of thresholds between each frequency-specific AEP and PTA was not same. The difference of thresholds were the smallest and the relevance were the best between 40 Hz AERP and PTA at 0.5 kHz, and between ASSR and PTA at 2, 4 kHz. At 1 kHz, there were not statistical difference between ASSR, 40 Hz AERP and PTA, while the relevance of 40 Hz AERP was better than ASSR. CONCLUSION Different methods should be chosen to assess the objective behavioral thresholds at different frequency.
Acoustic Stimulation/methods* ; Adolescent ; Adult ; Audiometry, Evoked Response/methods* ; Audiometry, Pure-Tone ; Auditory Threshold/physiology* ; Evaluation Studies as Topic ; Evoked Potentials, Auditory ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Female ; Forensic Medicine ; Humans ; Male ; Middle Aged ; Predictive Value of Tests ; Young Adult

OBJECTIVETo evaluate the effect of low frequency and high frequency tympanometry in the diagnosis of middle ear function of infants.

METHODSTympanometries with 226 Hz, 678 Hz and 1000 Hz probe tones were obtained from infants aged 5-25 weeks with normal ABR (15 infants, 30 ears) and those with prolonged Wave I latency suggesting middle ear dysfunction (17 infants, 20 ears) using GSI Tympstar middle ear analyzer.

RESULTSThe type, peak pressure, peak compensated static acoustic admittance and gradient of 226 Hz tympanometry were of no significant differences between two groups. The pattern of 678 Hz tympanograms for admittance, susceptance and conductance included non-peaked, single-peaked, W-shaped and three-peaked type in both groups. The consistency between auditory brainstem response (ABR) and 678Hz tympanometry for admittance, susceptance and conductance were 70.0%, 58.0%, 64.0% (kappa = 0. 324,0. 234,0. 118) respectively. A single peaked tympanogram was typical in normal infants for 1000 Hz admittance, susceptance and conductance tympanograms and there were 28 ears (93.3%), 25 ears (83.3%) and 26 (86.7%) respectively. Tympanogram without any positive peak was the most characteristic for a probe frequency of 1000 Hz in infants with prolonged wave I latency and there were 15 ears (75%), 17 ears (85%) and 13 ears (65%) respectively. For admittance, susceptance and conductance, the consistency between 1000 Hz tympanometry and ABR were 90.0%, 92.0% and 86.0% and kappa were 0.783, 0.831 and 0.690, respectively.

CONCLUSIONS1000 Hz probe tone tympanometry was accurate diagnostic tests for middle ear function in infants younger than 25 weeks of age, while 226 Hz and 678 Hz probe tone tympanometries were not.

Acoustic Impedance Tests ; Ear, Middle ; physiology ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Female ; Hearing Tests ; methods ; Humans ; Infant ; Male

OBJECTIVE: To compare the time domain and the frequency domain of speech-evoked auditory brain-stem response measured by stimulation of left and right ears, and to explore the difference and possible reasons of neural coding for speech from different ears in auditory brainstem. METHOD: Speech-ABRs to syllable /da/ of 31 healthy adults were recorded. Statistical analysis was performed on time-domain parameters, such as latencies and amplitudes of featured peaks, and frequency-domain ones, such as amplitudes of the fundamental frequency and the first formant of speech-ABRs ranging from 20-50 ms. A scoring criterion to grade the appearance of featured waves was proposed for waveform evaluation. RESULT: There were no significant difference for the latencies of binaural featured peaks and amplitudes of feature peaks (except peaks A and O). The waveform .scores of right ear were greater than that of left ear. The amplitudes of fundamental frequency of binaural waves were both greater than that of the first formant. There was no significant difference of amplitudes of fundamental frequency and the first formant between two ears. CONCLUSION The origins and distributions of speech-ABR are essentially symmetrical in brainstem in contrast with the hemisphere asymmetry of speech.
Acoustic Stimulation ; Adolescent ; Adult ; Ear ; physiology ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Female ; Humans ; Male ; Speech ; Young Adult