Objective To study the characteristics of auditory brainstem response by chirp and click stimuli in normal hearing children.Methods A total of 97 children (194 ears)with normal hearing were recruited,including 50 male (100 ears),and 47 female (94 ears).The CE-chirp and the click acoustic stimulation were used to,and the ABR waveforms and latencies were obtained.ResuIts The chirp-ABR Ⅰ wave recognition rate (36%)was significantly lower than that of click-ABR (100%).At 80 dB nHL,chirp-ABR V wave latency was shorter than click-ABR,the difference was statistically significant (P< 0.05 ).The chirp and click ABR V wave response thresholds showed no significant difference (P>0.05).At 80 dB nHL,no statistical significance of two kinds of a-coustic stimulation of ABR V wave amplitude difference (P>0.05).At 50 dB nHL,chirp-ABR significantly in-creased than click-ABR V wave amplitude with statistically significant differences (P<0.05).At 80,and 50 dB nHL,chirp-ABR showed no differences in the amplitude of V wave (P>0.05 ).ConcIusion The chirp acoustic stimulation produced the larger response amplitude,and was faster,demonstrating the noticeable advantages to tes-ting children.

Objective To study the clinical significance of Chirp-ASSR and the characteristics of hearing loss patients by ASSR(auditory steady-state responses) under Chirp stimulation.Methods A total of 136 hearing loss children (5～10 years old) with 272 ears were distributed into four groups based on 500 Hz,1 000 Hz,2 000 Hz and 4 000 Hz auditory threshold arithmetic average:20～dB HL,40～dB HL,60～dB HL,and≥80 dB HL groups.To compare the correlation of the PTA and Chirp-ASSR in different frequencies domain through SPSS statistics 19.0 software,the data were used T-test and Pearson analysis.Results ①The group(≥80 dB HL) achieved a statistically significant higher reaction threshold than pure tone threshold.②The correlation index γ'of PTA and Chirp-ASSR showed a decline along with the hearing loss increase;It increased along with the test frequency,there was a significant difference between 500 Hz and 4 000 Hz(P＜0.05).Conclusion Chirp-ASSR is a frequency-specific electrophysiological test method,it could reflect the truthful listening ability,especially in mild,moderate,and severe hearing loss children.