Tone burst auditory brainstem response and click auditory brainstem response in infants with normal hearing

OBJECTIVE To evaluate the effectiveness and advantage of tone burst auditory brainstem response (TB-ABR)as a method of auditory diagnosis in infants.METHODS Twenty seven infants(54 ears)who passed the tests including distortion product otoacoustic emission(DPOAE)and click auditory brainstem response(C-ABR)received TB-ABR measurements and correlation analyses between TB-ABR threshold and C-ABR threshold were carried out.RESULTS Wave Ⅴ threshold of the 27 infants(54 ears)who completed four frequencies TB-ABR was(40.0±11.6)dB nHL in 0.5 kHz,(36.7±9.0)dB nHL in 1 kHz,(27.2±6.7)dB nHL in 2 kHz and(25.9±6.3)dB nHL in 4 kHz respectively, which were significantly higher than C-ABR threshold (17.8±6.4)dBnHL(P 0.05).The higher of the stimulus frequency, the lower of waveⅤthreshold and the shorter of waveⅤ latency of TB-ABR.Linearity was found between C-ABR threshold and TB-ABR threshold at 0.5, 1, 2 and 4 kHz(γ=0.53,0.60,0.67,0.72,P 0.01).CONCLUSION There is a correlation between TB-ABR threshold and C-ABR threshold,the correlation at high frequency is better than that of low frequency in infants with normal hearing.TB-ABR may serve as a preferable objective measurement for assessing the hearing threshold with frequency specificity in infants.