Experimental and clinical study on the steady-state response elicited by sinusoidally amplitude-modulated tones.

(1)临床研究对125例突发性高频、低频和中频听力障碍儿童进行了相位相干检测80-HzAMFR预测睡眠时听阈值的可靠性和频率特异性的评价。所有患者均行载频为1000 Hz的80-HzAMFR检查，其中93耳用1000 Hz单音诱发听性脑干反应(ABR)。在睡眠中检测两种反应，并将阈值与由标准纯音测听或游戏测听确定的行为听力阈值进行比较。在听力图类型不同的儿童中，80-HzAMFR的阈值模式在所有类型的听力障碍中都明显遵循相应的听力图模式。因此，80-HzAMFR的测量对儿童睡眠中的听力预测是准确的，并具有良好的可靠性和频率特异性。此外，t…对80-HzAMFR在不同睡眠阶段的稳定性进行了评价。结果表明，成人和儿童在深度睡眠阶段的反应更清晰。利用计算机产生可同时在4个频率上估计听力并缩短跨频率听力预测的检查时间的多刺激技术，并开始用于临床。(2)实验研究为阐明耳蜗核(CN)和下丘(IC)对头皮记录的调幅跟随反应(AMFR)的贡献，用正弦调幅(SAM)音诱发的近场电位，在猫的CN和IC上记录短声和短声。SAM音频的载波频率设置为1 kHz，调制深度为95%。声调制频率为20、40、77和100赫兹。由CN和IC记录的SAM单音激发的近场电位由两个分量组成，一个是与调制速率对应的低频分量，另一个是类似于SAM单音本身的高频分量。另一方面，短声和短声可诱发相对较短的时程电位，重复为刺激率。在中脑腹侧核、中央周围核与中央核之间，SAM纯音诱发的电位位相颠倒。这些结果提示，中央核和中央核参与了头皮记录AMFR的产生。较少

(1) Clinical studyThe reliability and frequency specificity of 80-Hz amplitude-modulation following response (80-Hz AMFR) detected by phase coherence to predict the hearing threshold during sleep was evaluated in 125 children with abrupt high-frequency, low frequency and mid-frequency hearing impairment. The 80-Hz AMFR at carrier frequency of 1000 Hz were performed in all patients and the auditory brainstem response (ABR) elicited by 1000 Hz tone pips in 93 ears. Both responses were examined during sleep and thresholds were compared with behavioral hearing threshold, which was determined by standard pure-tone audiometry or play audiometry. In children with various patterns of audiogram, the threshold patterns of 80-Hz AMFR clearly followed the corresponding audiogram patterns in all types of hearing impairment. The measurement of 80-Hz AMFR thus appeared to be accurate in hearing prediction and to have a good reliability and frequency specificity in children during sleep.In addition, t … More he stability of 80-Hz AMFR was evaluated in various stages of sleeping. The results suggested that the response was more clearly detected in deeper sleep stage in adults and children.The stimulus tones for multiple stimulation technique, by which hearing can be estimated in 4 frequencies simultaneously and the examination time for the prediction of hearing across the frequencies used for audiometry can be shortened, were generated by using computer and were begun to use clinically.(2) Experimental studyTo clarify the contribution of the cochlear nucleus (CN) and inferior colliculus (IC) to the scalp-recorded amplitude-modulation following response (AMFR), the near-field potentials elicited with the sinusoidally amplitude-modulated (SAM) tone, click and tone pip were recorded from CN and IC in cats. The carrier frequency of SAM tone was set at 1 kHz and the modulation depth was 95%. The modulation rates of SAM tones and the repetition rates of click and tone pip were 20,40,77 and 100 Hz. The waveforms were calculated by the summation of 100 sweeps.Near-field potentials elicited with SAM tones and recorded from CN and IC were consisted of two components ; one was the low-frequency component corresponding to modulation rate and the other was the high-frequency component resembled to SAM tone itself. On the other hand click and tone pip elicited the relatively short-duration potentials repeating as stimulus rate. The phase of the potentials elicited by SAM tone reversed in the ventral nucleus of CN and between the pericentral and the central nucleus of IC.These results suggest that CN and IC contribute to the generation of the scalp recorded AMFR. Less