Development of Automatic Objective Audiometry Device

听力阈值可以通过80-Hz调幅跟随反应（80-Hz AMFR）来评估，该AMFR是在睡眠中以频率特定的方式通过相位相干检测的。然而，这种方法是耗时的。本课题的目的是研制一种采用多刺激技术和自动阈值检测技术的客观测听装置，利用PC 9821 Xa 7 e微机和LabVIEW编程软件，产生由多个载波频率和调制频率组成的混合正弦调幅音，用于多个同时刺激。当调制频率相差小于10 Hz时，利用相位相干分析方法，可以同时清晰地检测到两种不同的调制频率，从而实现阈值的自动检测。然而，使用相位相干和幅度平方coh的分析技术 ...更多信息 在检测响应方面，Erence并不节省时间。因此，我们开发了一种新的阈值检测分析方法，以节省检查时间。同时记录头皮记录电位和调制波形。调制波形上相同相位（90度）的连续10个点用作触发。每个触发器采集10个平均波形，共512个点，用相位相干法进行分析，与Fridman的传统方法相比，检测时间缩短了30%左右。使用这种技术，本文研究了短纯音产生的掩蔽频率和强度对AMER阈值的影响，以估计80-Hz AMFR的频率特异性，结果表明短纯音对80-Hz AMFR有掩蔽作用，80-Hz AMFR具有频率特异性。使用这种技术的自动客观测听装置目前正在临床上使用，以校正数据，频率特异性和多刺激技术的有用性。少

Hearing threshold can be evaluated by 80-Hz amplitude-modulation following response (80-Hz AMFR) detected by phase coherence in a frequency specific manner in sleeping children. However, this method is time consuming. The aim of this project was to develop a objective audiometry device using multiple stimulation technique and automatic threshold detection techniques, by which audiogram can be obtained only by AMFR thresholds.Mixed sinusoidally amplitude modulated tone consisted of several carrier frequencies and modulation frequencies for multiple simultaneous stimuli was produced using personal computer (NEC PC9821Xa7e) and programming software (LabVIEW). When the difference of modulation frequencies of mixed sinusoidally amplitude modulated tone was less than 10 Hz, two responses were detected clearly and simultaneously using phase coherence as a analyzing method for the automatic detection of threshold. However, the analyzing technique using phase coherence and magnitude-squared coh … More erence was not so time saving in the detection of responses. Therefore, we developed a new analyzing method for the detection of threshold for examination time saving. Scalp-recorded potential and modulation waveform were recorded simultaneously. Succeeding 10 points in the same phase (90 deg) on modulation waveform were used as triggers. Ten averaging waveforms consisted of 512 points of scalp-recorded potentials were obtained using each trigger and were analyzed by phase coherence.Using this analyzing technique, examination time was shortened to about 30% comparing with conventional method developed by Fridman. Using this technique, the effect of masker frequency and intensity produced by a tone burst on AMER threshold was investigated for the estimation of frequency specificity of 80-Hz AMFR.The results suggested masking effect by tone burst on 80-Hz AMFR and frequency specificity of 80-Hz AMFR to be high enough.Automatic objective audiometry device using this technique is now using clinically to correct the data for the estimation of frequency specificity and usefulness of multiple stimulation technique. Less