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

OBJECTIVE: There were few recent study concern about usefulness of cochlear hydrops analysis masking procedure (CHAMP) in progression of Ménière's disease. The purpose of this study is to analyze changes in the CHAMP as advancement of Ménière's disease. METHODS: We studied 19 cases of ‘ Definite’ group of Ménière's disease. We assumed progression of Ménière's disease would be checked by pure tone threshold by four tone average (4PTA), low tone average (LPTA). We also compared electrocochleography (ECoG), dizziness handicap inventory (DHI), tinnitus handicap inventory (THI) as parameters for progression of Ménière's disease to CHAMP latency delay and amplitude ratio. Chi-square test was used as a statistical method. RESULTS: In the group of patients had abnormal amplitude ratio, ECoG value were not improved, but there was not statistically significant (odds ratio [OR]=5.727, p>0.05). Better DHI and THI score were not necessarily construed as the improvement value in the CHAMP (p>0.05). In amplitude ratio abnormal group, 4PTA was aggravated, but not statistically significant (OR=1.5, p>0.05). In the group of patient had abnormality in both latency delay and amplitude ratio, LPTA was relatively aggravated (OR in latency delay: 2, OR in amplitude ratio: 10); however, reveals no statistically significance between them (p>0.05). Change of ECoG, hearing threshold including 4PTA and LPTA with progression of Ménière's disease were not correlated significantly with latency delay or amplitude ratio of CHAMP. CONCLUSION: We conclude that CHAMP does not reflect clinical features with progression of Ménière's disease.
Audiometry, Evoked Response ; Dizziness ; Edema ; Endolymphatic Hydrops ; Hearing ; Hearing Loss ; Humans ; Masks ; Meniere Disease ; Methods ; Tinnitus ; Vertigo

BACKGROUND AND OBJECTIVES: The aim of this study was to analyze the summating potential (SP)/action potential (AP) ratio of electrocochleography (ECoG) recorded from the position of SP peak. We compared the SP/AP ratios of negative polarity and positive polarity graphs from the same ECoG of each patient by assuming different the position of SP peak. In addition, we attempted to evaluate the utility of two different manners of recording the ECoG graph in the diagnosis of Meniere's disease. SUBJECTS AND METHOD: Retrospectively, we analyzed the results of ECoG in 67 patients with unilateral definite Meniere's disease. ECoG was analyzed in two different manners. From the AP peak, the SP peak was determined close when positioned in the negative polarity; on the other hand, SP peak was considered distant when positioned in the positive polarity. The SP/AP ratio was interpreted with reference to the base line value. The ratio of two different ECoG values from each patient of Meniere's disease was calculated. RESULTS: In the abnormal side, the negative polarity ECoG showed significantly greater value of SP/AP ratio (mean: 0.334±0.10) than the positive polarity ECoG (mean: 0.283±0.09) (p<0.001). In the normal side, the negative polarity ECoG, showed significantly greater value of SP/AP ratio (mean: 0.250±0.09) than the positive polarity ECoG (mean: 0.204±0.06), as well as in the abnormal cases (p<0.001). CONCLUSION: The standard SP/AP ratio for the diagnosis of Meniere's disease can be variable according to the manner of determining the SP peak.
Action Potentials ; Audiometry, Evoked Response* ; Diagnosis ; Evoked Potentials ; Hand ; Humans ; Meniere Disease ; Methods ; Retrospective Studies

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

OBJECTIVE: To analyze the difference of subjective hearing threshold and objective hearing threshold, and to discuss the importance of standard for hearing evaluation in forensic medicine. METHODS: Three hundred and fifty-five cases (387 ears) of forensic medical identification with hearing impairment were retrospectively analyzed including the items entrusted and hearing test results. All cases were collected from 2004 to 2012 in the forensic science center. RESULTS: In the 387 ears, 218 ears (56.3%) were evaluated the degree of disability and 106 ears (27.4%) were identified the degree of damage. In the disability degree evaluation, the subjective hearing threshold and the objective hearing threshold were significant different in 120 ears (55.0%), while in damage degree evaluation, the subjective hearing threshold and the objective hearing threshold were significant different in 69 ears (65.1%). CONCLUSION Because of camouflaging or exaggerating the hearing impairment by the wounded, the subjective hearing threshold can't accurately assess the existence and the degree of hearing impairment. In the forensic identification, auditory brainstem response, 40 Hz auditory event related potential and auditory steady-state response should be combined in the application to evaluate the hearing impairment for the wounded in order to ensure the reliability of the evaluation of hearing impairment.
Acoustic Stimulation/methods* ; Adolescent ; Adult ; Aged ; Audiometry, Evoked Response/methods* ; Audiometry, Pure-Tone ; Auditory Threshold ; Child ; Child, Preschool ; Disability Evaluation ; Evoked Potentials, Auditory ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Expert Testimony/methods* ; Female ; Forensic Medicine/methods* ; Hearing Disorders/physiopathology* ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Severity of Illness Index ; Young Adult

OBJECTIVE: To study the value of slow vertex response (SVR) in the evaluation of hearing loss by comparing the hearing thresholds acquired with SVR and pure tone audiometry (PTA). METHODS: Twenty-five subjects (40 ears) with sensorineural hearing loss were tested by PTA and SVR. According to the thresholds of PTA, these ears were subdivided into mild, moderate and severe hearing loss groups, and rank sum test was performed on the thresholds of SVR and PTA for all the hearing loss groups. Then, the correlation between PTA thresholds and SVR thresholds was analyzed and the mathematical models were established for predicting behavioral thresholds by the thresholds of SVR. RESULTS: At four test frequencies (0.5, 1, 2 and 4kHz), the thresholds of SVR had high correlations with thresholds of PTA. Four liner regression equations were established, and the correlation coefficient(r) were 0.971, 0.976, 0.957 and 0.928, respectively (P < 0.05). Back substitution test showed that the liner regression equations would be an easy method for estimating the behavior thresholds. CONCLUSION The behavioral threshold can be well judged and evaluated by the liner regression equations established with SVR thresholds.
Acoustic Stimulation/methods* ; Audiometry, Evoked Response ; Audiometry, Pure-Tone ; Auditory Cortex/physiology* ; Auditory Threshold/physiology* ; Evoked Potentials, Auditory/physiology* ; Female ; Forensic Medicine/methods* ; Hearing Loss/physiopathology* ; Humans ; Male ; Predictive Value of Tests ; Regression Analysis ; Severity of Illness Index

Auditory evoked potential (AEP) is the electric activities originating from auditory systems evoked by sound stimulus. AEP include cortical electric response audiometry (CERA), auditory brainstem evoked response (ABR), 40 Hz auditory event related potentials (40 Hz AERP), auditory steady-state response (ASSR), etc. For the subjects who cannot provide reliable or accurate behavioral hearing threshold, those techniques have been explored to evaluate the behavioral hearing threshold objectively. These techniques are reviewed in this article and are found that they could reflect the behavioral hearing threshold very well. CERA is difficult to operate because it is affected by the subject's wakefulness. ABR is the most widely used method currently and is not affected by the subject's consciousness, but it only reflects high frequencies. 40 Hz AERP has good sensitivity, while its results highly depend on the subject's consciousness. ASSR can be operated by using multiple frequency stimuli simultaneously to both ears and the test time is short. It is still a very difficult task to combine different techniques according to their characteristics in forensic audiology.
Acoustic Stimulation/methods* ; Adult ; Audiometry, Evoked Response/methods* ; Audiometry, Pure-Tone ; Auditory Cortex/physiology* ; Auditory Threshold/physiology* ; Cerebral Cortex/physiology* ; Evoked Potentials, Auditory ; Evoked Potentials, Auditory, Brain Stem ; Forensic Medicine/methods* ; Hearing/physiology* ; Hearing Disorders/diagnosis* ; Humans ; Infant ; Predictive Value of Tests ; Reproducibility of Results

OBJECTIVE: To investigate the value of slow vertex response (SVR) for forensic appraisement of hearing dysfunction by comparing the thresholds acquired with SVR and pure tone audiometry (PTA). METHODS: Forty-six subjects with normal hearing were tested with PTA (0.125-8 kHz) and SVR (0.5-4 kHz). Paired t-test analysis was performed on the thresholds of SVR and PTA at each frequency (0.5, 1, 2 and 4 kHz), and analysis of variance was performed on the difference between the pure tone audiometry threshold and the evoked potential threshold among different frequency. RESULTS: At each frequency(0.5, 1, 2 kHz and 4 kHz), difference between the thresholds acquired with SVR and PTA was statistically significant(P < 0.05). The mean difference of the two thresholds were (5.98 +/- 6.72) dB HL at 0.5 kHz, (3.86 +/- 6.12) dB HL at 1 kHz, (7.12 +/- 6.56) dB HL at 2 kHz, (8.53 +/- 7.90) dB HL at 4kHz, and the mean difference at 1 kHz was the smallest. This variation between frequencies was also statistically significant. CONCLUSION The thresholds acquired with SVR were higher than those acquired with PTA. The adjusted thresholds should be established at each frequency, when the SVR thresholds are used to evaluate the behavioural hearing thresholds.
Acoustic Stimulation ; Adult ; Analysis of Variance ; Audiometry, Evoked Response/methods* ; Audiometry, Pure-Tone ; Auditory Cortex/physiology* ; Auditory Threshold/physiology* ; Evoked Potentials, Auditory ; Female ; Hearing Disorders/diagnosis* ; Humans ; Male ; Middle Aged ; Reaction Time ; Young Adult

Slow vertex response (SVR) is one of long latency auditory evoked potentials. It is a biological and electric response originating from brain cortical neuron evoked by sound stimulus with the latency from 50 to 500 milliseconds. Of all the neuroelectric physiological audiometries, it is the earliest method applied in assessing the function of the auditory neural conduction pathway. The concept, neural generators of SVR have been introduced in this article. Influencing factors on SVR were discussed such as stimulus parameters, consciousness state, age, maturation of the subject. Applications of SVR in clinical and forensic medicine identification were also discussed.
Acoustic Stimulation/methods* ; Audiometry, Evoked Response/methods* ; Auditory Cortex/physiology* ; Auditory Pathways/physiology* ; Auditory Threshold ; Cerebral Cortex/physiology* ; Evoked Potentials, Auditory ; Forensic Medicine/methods* ; Hearing Disorders/diagnosis* ; Humans ; Reaction Time

BACKGROUNDMost patients with auditory neuropathy (AN) could receive good even the best effects after cochlear implantation. How to diagnose AN objectively and accurately is very important. In this study, we screened the patients with AN according to the presence or absence of compound action potential (CAP) of intraoperative round window electrocochleography (RW ECochG).

METHODSIntraoperative RW ECochG was performed on 32 patients with profound sensorineural deafness, who had normal cochlea during cochlear implantation surgery under general anesthesia in the standard operating room. The cochlear microphonic (CM) and CAP of RW ECochG was observed and recorded.

RESULTSThe presence of CM but the absence of CAP of RW ECochG occurred in 12 among the 32 patients. They were suspected to suffer from AN. The rest patients who had CM and CAP of RW ECochG were thought not to suffer from AN.

CONCLUSIONApplication of intraoperative RW ECochG during the cochlear implantation surgery may objectively and accurately screen the patients with AN, and can give a meaningful clue for implanted device working.

Adolescent ; Adult ; Audiometry, Evoked Response ; methods ; Child ; Child, Preschool ; Cochlear Nerve ; pathology ; Electrophysiology ; methods ; Evoked Potentials ; Female ; Humans ; Infant ; Male ; Round Window, Ear ; Vestibulocochlear Nerve Diseases ; diagnosis ; Young Adult