Integrated Assessment Of Audiology In Sensorineural Hearing Loss Children

Subjective audiometry and objective audiometry are used in assess the hearing threshold of children. There are many tests in audiometry, such as acoustic impedance, otoacoustic emission, auditory brainstem response (ABR), behavioural audiometry (BA), pure-tone audiometry (PTA) . With the maturity and stability of multiple-frequency auditory steady-state evoked response (MF-ASSR), ASSR is accepted by doctors and used as a technique for hearing test.At present, there are kinds of research reports related to various techniques of hearing test have been made in detail at home and abroad. But there are little reports about the evaluation of the hearing threshold in children through combination of hearing tests. However, the majority reports of which are the application of BA combining with ABR.Objective: We use MF-ASSR on the basis of previous reports of hearing test combinations, which means that we make use of ABR, ASSR, BA in free field and PTA to make comprehensive evaluation of the hearing in children of sensorineural hearing loss. Then we make comparison and analysis of the results in order to assure the value of the hearing test combinations in assess the residual hearing of sensorineural hearing loss children, and to provide the information and means of the next intervention basis.Method: In this research, all the children of sensorineural hearing loss have been tested with endotoscope and acoustic immitance to exclude the pathological changes of outer ear and middle ear, and with distortion prod-acts otoacoustic emissions (DPOAE) to exclude the pathological changes of post-cochlea. Then, the patients who can follow the PTA will take PTA, ABR, ASSR test. Using the pure tone thresholds as the judging standards to analysis the relationship between ABR, ASSR and pure-tone hearing threshold, and to establish ASSR-PTA linear regression equation, then we can use ASSR threshold to predict the corresponding pure-tone hearing thresholds. The patient who can not follow PTA will take BA in free field, ABR, ASSR. We can use the results of ASSR to predict the corresponding pure-tone hearing threshold through ASSR-PTA linear regression equation and combine the threshold of BA and ABR to make comprehensive evaluation of residual hearing in children of sensorineural hearing loss. We name the patient following PTA as PTA group, and those not following as BA group for the good of analysis.Results: 1)There are differences (dBHL) between ASSR response threshold and pure-tone threshold of our library in the detecting results of group PTA, each ASSR threshold in difference frequency notable related with the pure-tone threshold(P<0.01). The Person coefficient correlation of each frequency was respectively 0.75,0.76,0.76,0.83。According to the above data, the linear regression equation was established. 2) Compared with the ABR and ASSR results in Group BA (29 cases), 23 ears were response to ASSR. No ear was response to neither in ASSR or in ABR. Thus ASSR was the important implement to ABR in the hearing assessment of patients who was no response to ABR.3) From the comparison between 21 behavioral hearing thresholds in the children who can follow BA test and the ear which was better response to ASSR, there 84 response thresholds were detected at frequencies from 500-4000HZ. 71 response thresholds can be detected in the ASSR test. 74 response thresholds can be detected solely in the BA. 78 response thresholds can be acquired if we combinate the results of ASSR and BR.Conclusions: Compared with the single hearing test, the hearing tests combination (BA+ABR+ASSR) can assess the residual hearing for the younger child, the more heaver hearing loss children. And it can evaluate the hearing differences in hibateral ears, the hearing thresholds in different frequencies, locating the hearing damage.