听力正常青年人独立调幅调频反应与言语识别率的关系

Auditory Steady-State Responses to Tones Independently Modulated in Both Frequency and Amplitude and Word Recognition Scores in Young Adults with Normal Hearing

目的 观察听力正常青年人独立调幅调频（independent amplitude and frequency modulation，IAFM）反应与言语识别率（word recognition score，WRS）的关系，探讨采用IAFM反应预估WRS的可能性。方法 21名听力正常青年受试者（21耳）以0．5、1．0、2．0和4．0kHz为载波，振幅调制频率分别为79、87、95和103Hz，调幅深度分别为55％、50％、45％及35％；频率调制频率分别为85、93、101和109Hz，调制深度分别为35％、30％、20％及35％，四个IAFM声同时给出，单耳给声。分别测试20、30、40、50、60、70、80和90dB SPL的IAFM有意义反应数和WRS，观察两者之间的相关性。结果 IAFM反应数与强度的线性相关系数为0．844（P〈0．01），WRS与强度的线性相关系数为0．785（P〈0．01），IAFM反应数与WRS的线性相关系数为0．785（P〈0．01）；IAFM反应数与WRS的偏相关系数（强度为控制因素）为0．371（P〈0．01）。结论 调制频率在70～110Hz的IAFM反应能够反映耳蜗和脑干对频率和振幅变化的分辨能力，与WRS有显著的相关性，有可能成为评价言语感知所必需的声学信息分辨能力的客观工具。从而成为评价和预估言语识别功能的措施之一。

Objective To observe the relationship between auditory steady- state responses to tones independently modulated in beth amplitude and frequency （IAFM） and word recognition scores （WRS） in young adults with normal hearing.The probability of using IAFM response to predict the ability of subjects to discriminate words is discussed. Methods The IAFM stimuli consisted of four carrier tones （0.5,1.0,2.0 and 4.0 kHz） which were modulated in amplitude at rate of 79,87,95 and 103 Hz, and in frequency at rate of 85,93,101 and 109 Hz. The modulation depth of amplitudes were 55% ,50% ,45% and 35%, the modulation depth of frequencies were 35 %, 30 %, 20 % and 35 %. The four carriers were presented simultaneously through ER- 3A insert earphone, monaurally. The auditory steady-state responses to IAFM and WRS were recorded at intensities between 20 and 90 dB SPL in a sample of 21 young adults （21 ears） with normal hearing, the step was 10 dB. Results The coefficient correlation between the number of IAFM responses and intensities was 0.844（ P 〈 0.01）, the coefficient correlation between WRS and intensities was 0.785（ P 〈 0. 01 ）, and the coeffcient correlation between the number of IAFM responses and WRS was 0.785 （ P 〈 0.01）. The coefficient of partial correlation between the number of IAFM responses and WRS （ controlling for intensity） was 0. 371（ P 〈 0.01 ）. Conclusion The correlation between WRS and the number of responses to IAFM modulated at rate of 70 ～ 110 Hz is significant. The IAFM response can provide information about whether the changes of amplitude and frequency have been processed in the cochlea and brainstem, it may be used as an objective test for assessing the ability of discriminating speech sound.