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

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

OBJECTIVETo establish a model of acoustically evoked short latency negative response (ASNR) in guinea pigs, a model of profound hearing loss with normal saccular functions, and verify the correlation between ASNR and vestibular evoked myogenic potential (VEMP).

METHODSThirty-two healthy guinea pigs were employed in the experiment, which were randomly divided into control group (16 subjects) and deafened group (16 subjects). Each animal experienced auditory and vestibular tests including auditory brainstem response (ABR), VEMP and caloric test. A quick treatment was employed for deafened group consisting of a subcutaneous injection of kanamycin at a dose of 400 mg/kg followed by a jugular vein injection of ethacrynic acid at a dose of 40 mg/kg one hour later. The animals were received ABR, VEMP and caloric test 7 - 10 days following the drug administration. The deafened group was further divided into ASNR group and non-ASNR group, based on the presence of ASNR.

RESULTSIn deafened group, five subjects died postoperatively, 11 subjects (22 ears) provided full data, ASNR was elicited in eight ears (36.4%), the threshold was 120 - 130 dB SPL with mean of (124.4 ± 4.96) dB SPL. Its latency range was 1.75 - 2.60 ms with mean of (2.15 ± 0.27) ms. The mean latency of threshold was (2.34 ± 0.18) ms. All eight ASNR ears presented with VEMP. The VEMP threshold, positive and negative potential latencies proved no statistical difference (P > 0.05) between ASNR group and control group. Significant difference was detected between the VEMP presence of ASNR group and non-ASNR group (P = 0.002). There was no statistically significant correlation between VEMP and caloric test neither between ASNR and caloric test in deafened group.

CONCLUSIONSThis study evoked ASNR in an ototoxicity guinea pig model which has profound hearing loss with normal saccular functions. The presence of ASNR correlated with VEMP, however, not correlated with caloric test, suggesting that ASNR and VEMP are both originated from the saccule.

Animals ; Deafness ; physiopathology ; Disease Models, Animal ; Evoked Potentials, Auditory ; physiology ; Evoked Potentials, Auditory, Brain Stem ; Guinea Pigs ; Saccule and Utricle ; physiology ; Vestibular Evoked Myogenic Potentials ; Vestibular Function Tests

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

OBJECTIVEThe aim of this study was to compare the basic characters of the speech-evoked auditory brainstem response (speech-ABR) between young adults and school-age children.

METHODSSpeech-ABR of thirty eight normal hearing subjects including eighteen school-age children and twenty young adults were recorded. The speech syllable/da/as stimulus sound was transmitted to right ear by insertion the earphones in speech-ABR test.

RESULTSResponse waves of speech-ABR in school-age children were similar to those in young adults, which contained the onset response (peak V and A), the transition (peak C), the frequency following responses (peak D, E and F) and the offset response (peak O). Both the latency and amplitude showed no significant difference in all waves between young adults and school-age children, except the latency of wave O and amplitude of wave F. The latency of O wave in school-age children (47.80 ± 0.38) ms were significantly shorter than that in adults (48.10 ± 0.40) ms (t = 2.330,P = 0.026). The amplitude of F wave in school-age children (-0.21 ± 0.15) µV were significantly larger than that in adults (-0.12 ± 0.08) µV (t = 2.146,P = 0.043).

CONCLUSIONBoth the latency and amplitude of the speech ABR in school age children at 6 - 11 years old show the great similarity with the young adults, which indicate that the ability of speech processing of brainstem in children has completely reached maturity.

Adult ; Child ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Female ; Humans ; Male ; Speech ; Young Adult

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

OBJECTIVETo investigate the correlation between thresholds in the chirp-ABR and behavior audiogram in order to find out if it is possible to be used as an clinical application of the chirp-ABR in estimating hearing sensitivity.

METHODSTwenty-two cases with hearing loss or normal hearing were enrolled in the study. The behavior audiogram and the response thresholds of chirp ABR (including chirp ABR, L-chirp ABR and U-chirp ABR) were obtained from 35 ears.

RESULTSTwenty-two cases were of both genders. The age was between 3.3- 6.5-years-old with the average age of 4.8-years-old. Divided by the degree of hearing loss, in the 35 ears, there were 6 with normal hearing, 2 with slightly hearing loss, 4 with moderate hearing loss, 10 with severe hearing loss and 13 with profound hearing loss. The Pearson correlation coefficients were 0.939, 0.900 and 0.930, respectively, which got from the data between the average of 0.5 - 4 kHz and chirp ABR respond threshold, 0.5 kHz and L-chirp ABR, and the average of 1 - 4 kHz and U-chirp ABR.

CONCLUSIONAs an objective test, the response threshold of chirp-ABR and the behavior audiogram were a highly correlated with each other, but more application in more subjects is needed.

Acoustic Stimulation ; Audiometry, Evoked Response ; Auditory Threshold ; physiology ; Child ; Child Behavior ; Child, Preschool ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Female ; Hearing Tests ; Humans ; Male