模拟环境助听器检配仪器的设计

目的：研制一台以声音对脑电波幅值的影响为理论依据，计算机智能判断听阈值的助听器检配仪器。方法：设计正弦波发生电路结合音频驱动电路，实现频率步进、增益连续可调的纯音刺激源：利用运放电路的白噪声经放大滤波模拟环境噪声；对被测者脑电进行实时监控，将声音对脑电波幅值的影响作为听阈判别指标；单片机和MATLAB对脑电采集系统采集的脑电波信号进行数据传输、处理和波形显示，脑电波在GUI界面实时显示时，软件通过幅值算法捕捉脑电幅值突变点并发出反馈讯号，提示记录听阈值。最后通过听阈曲线绘制得到综合测听结果并储存。结果：纯音刺激源的频率和响度范围满足听力检测要求（20Hz-15kHz，0dB-150dB）；噪声模拟接近相关标准；本设计实现了脑电采集和实时显示，计算机软件可捕捉到脑电波因突发的声音刺激而产生的幅值突变，判断失误率仅为6．7％。得到的综合测听结果与临床测听数据基本一致。结论：本项目研制的仪器操作简单、智能化，更符合实际应用要求，且具有学科交叉配合保证科学性的优势，对脑电波特征性变化在客观性听力测试上的应用具有一定的参考意义。

The Design of A Hearing AIDS Screening Instrument with Simulation Environment

Objective：To design a Hearing AIDS screening instrument on the theoretical basis of the sound effect on electroen- cephalogram （EEG） amplitude which can make intelligent judgment on hearing threshold. Methods：Integrated Circuit of exert- ing sine wave combined with audio driver circuit provided adjustable frequency and gain of pure tone stimulus; Using op-amp circuit of white noise to simulate environment by amplifying and filtering; To real-time monitoring of EEG, treating the sound effect on brain wave amplitude as the index of hearing. Microcontroller and MATLAB manage the EGG signal from acquisition system, and the corresponding software algorithm judge the signal change and give warning, which prompts to record the thresh- old value , Finally, drawing the auditory threshold curve according to the comprehensive listening results are obtained and stored. Results： Frequency and scope of loudness of pure tone stimulus meet the requirements of listening test （20 Hz- 15 kHZ, 0 db-150 db）; Noise simulation close to relative standard; The software can capture the EGG signal amplitude mutation caused by sound stimuli, judgment errors is 6.7%. Get comprehensive listening results and clinical listening results are basically identi- cal. Conclusions： The instrument operation is easy, intelligent, more conform to the requirements of the practical application, and has the advantages of subjects cooperation to ensure the scientific nature of the results, and the application of EGG in the listening test has certain reference significance.