Audiology Evaluation On Auditory Steady State Response In Normal Hearing Adults And Sensorineural Hearing Loss Children

Objective: To investigate the values of auditory steady state response (ASSR) in hearing evaluation.Methods:50 normal hearing adults (100 ears) were tested with pure tone audiometry (PTA), impedance testing, auditory steady state response and auditory brainstem response testing;30 sensorineural hearing loss children (60 ears) were measured with impedance testing, distortion product otoacoustic emissions, auditory steady state response, auditory brainstem response and 40Hz auditory event related potential (40Hz AERP) testing. Data were analyzed by SPSS 13.0 sofeware.Results: In normal hearing adults:â‘ the mean thresholds of auditory steady state at 0.5,1.0,2.0 and 4.0 kHz were 13.92,16.65,17.40,14.55dB nHL.â‘¡The thresholds of ASSR were no more than 10 dB on average above the thresholds of pure tone audiometry (PTA) at each frequency while the thresholds of ASSR at 2.0,4.0 kHz were on average from 1 to5 dB below the thresholds of wave v of ABR.â‘¢There was significant correlation between thresholds of ASSR and PTA ,and the correlation coefficient(r) were 0.67,0.70,0.73,0.69 at 0.5,1.0,2.0 and 4.0 kHz; There was correlation between thresholds of ASSR at 2.0,4.0 kHz and wave v thresholds of ABR, and the correlation coefficient(r) were 0.41,0.58 respectively; In sensorineural hearing loss children:â‘ The positive incidences of ASSR at 0.5, 1.0, 2.0 and 4.0kHz were 100%,100%, 98% and 90% respectively. The positive incidences of ABR and 40Hz AERP were 62% and 97% respectively.â‘¡The average thresholds of ASSR at 2.0,4.0 kHz were lower about 5 dB than wave v thresholds of ABR;the mean of difference between thresholds of ASSR at 0.5,1.0 kHz and 40Hz auditory event related potential was about 12dB.â‘¢There was significant correlation and the correlation coefficient(r) were 0.92,0.95 respectively between thresholds of ASSR at 2.0,4.0 kHz and wave v thresholds of ABR. There was significant correlation and the correlation coefficient(r) were 0.82,0.90 between ASSR thresholds at 0.5,1.0 kHz and 40Hz auditory event related potential thresholds.Conclusion:â‘ In normal hearing adults: the normal values of ASSR were not influenced by ears; there are difference among the mean thresholds of ASSR ,pure tone audiometry and wave v thresholds of ABR.â‘¡In sensorineural hearing loss children: ASSR,ABR and 40Hz AERP can be used to estimate the objective thresholds. ASSR and ABR have similar accuracy to estimate the objective thresholds at high frequency; ASSR and 40Hz AERP have similar accuracy to estimate the objective thresholds at low frequency. So ASSR is superior to ABR and 40Hz AERP when used to evaluate residual hearing of severe hearing loss patients.