Auditory brain stem responses elicited by air-and bone-conducted tone pip from adults with normal hearing / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE To study the characteristic of auditory brain stem responses (ABRs) to air-and bone-conducted tone pip recorded in adults with normal hearing, to access the feasibility of estimating pure tone behavioral thresholds using tone-pip evoked ABR and to examine the effects of bone-conducted ABR to tone pips on differentiating the type of hearing loss. METHODS Air-and bone-conducted ABR to tone pips were recorded from otologically normal persons (n=20, male/female 10/10) using Smart EP auditory evoked potential system. RESULTS ABR thresholds to air-conducted tone pips were (24.8?7.3) , (16.1?6.5) , (13.5?5.5) , (11.9?5.8) dB nHL for 0.5, 1, 2 and 4 kHz, and were (9.5?9.3) , (13.4? 6.6) , (12.2?6.0) , (12.2?7.2) dB higher than the pure tone behavior thresholds respectively; The ABR thresholds to bone-conducted tone pips were (28.4?9.2) , (19.0?7.4) , (15.1?7.7) , (13.6?6.4) dB nHL for 0.5, 1, 2 and 4 kHz, and were (32.0?10.3) , (19.4?10.0) , (14.2?8.2) , (16.1 ?6.9) dB higher than the pure tone behavioral thresholds respectively. There were no statistically significant differences between the ABR thresholds to AC and BC tone pips. The wave forms of tone-evoked ABR were similar to those of click-evoked ABR. The detectability of Wave Ⅰ and Wave Ⅲ decreased with the decrease of tone pip frequency. The wave latencies of tone-pipevoked ABR were longer than those of click-evoked ABR, and they prolonged with the decrease of tone pip frequency. The Wave Ⅴ latency of ABR to BC 0.5 and 1 kHz tone pips at thresholds were longer compared that to AC. CONCLUSION The thresholds of tone-pip evokedABR were useful in estimating the pure tone behavioral threshold and bone-conducted tone-evoked ABR might be helpful in differentiating the type of hearing loss.