声场下噪声刺激对镫骨肌声反射幅值的影响

目的研究声场下不同强度的白噪声刺激对镫骨肌声反射幅值的影响。方法观察80名听力正常受试者在声场方式下给予不同强度（30、40、50和60dBSL）的白噪声刺激时，1、2和4kHz频率的声反射幅值的变化。结果受试者在给予白噪声刺激时声反射幅值较未给予白噪声刺激时明显降低（P〈0．01），40dBSL强度的白噪声刺激时，声反射幅值降低最明显，2、4kHz的声反射幅值降低幅度较1kHz处明显（P〈0．01），而2、4kHz处之间无明显差异（P〉0．05）。结论声场下白噪声刺激可致镫骨肌声反射幅值降低，临床上可以通过检测声场下白噪声刺激后镫骨肌声反射幅值的变化评估听觉传出神经的功能。

The Change of Acoustic Stapedius Reflex Amplitude with the Stimulation of the Wide Band Noise in Sound Field

Objective To investigate the effects of different intensity of wide band noise on acoustic stapedius reflex amplitude in sound field. Methods Acoustical reflex amplitude(at ART+10 dB)were obtained at three fre-quencies (1,2, 4 kHz) from 80 normally hearing subjects with wide band noise at 30,40,50 and 60 dB SL in sound field. Results Acoustical reflex amplitude was significantly decreased in the presence of wide band noise (P 0. 01). The most significant decrease of acoustic reflex amplitude could be observed in the present of 40 dB SL wide band noise. In comparison with the 1 kHz group, significant decrease was found in 2 kHz group and 4 kHz group(P <0. 01),but there was no difference between the 2 kHz group and 4 kHz group(P>0.05). Conclusion Since the decrease of the acoustic stapedius reflex amplitude is mediated by the auditory efferent system in sound field, in clini-cal practice the function of the auditory efferents can be evaluated by testing the change of acoustic stapedius reflex amplitude with the stimulation of the wide band noise in sound field.