RESEARCH AND DEVELOPMENT OF PRACTICAL HEARING AIDS FOR TELEPHONIC SPEECH WITH A SMALL NON-LINEAR DISTORTION

为了实现单共振分析式电话语音助听器的实时处理，我们尝试制作了一个小型的DSP系统，并以此为基础进行研究。与其他类型的助听器相比，单共振分析（SRA）型助听器呈现具有小的非线性失真的语音声音，但它需要比其他类型的助听器更复杂的计算。研究系统有四个DSP单元来执行实时计算，并包括用于开发助听器算法的硬件。随着单DSP处理能力的不断提高，现在使用两个高速DSP（每个60 MFLOPS）来构建紧凑型助听器。软件已经适应了新的硬件。它被证明能够将助听器的体积减少到研究系统的1/20。这个尺寸足够小，可以放在电话的两侧。在本计画的最后一部分，本研究报告指出DSP在助听器的性能上有很大的改善，并预期可在不久的将来开发出一款DSP助听器，以供SRA型助听器的现场测试之用。同时，还应进一步完善助听器的验配程序，以便于听障人士进行实际测试。

To realize the single resonant analysis type hearing aid for telephonic speech by real-time processing, we tried to make a small DSP system, which is based on our system for research. Single resonant analysis (SRA) type hearing aid presents speech sounds with a small nonlinear distortion compared with other types of hearing aid, but it needs more complicated calculations than other types of hearing aids. The system for research has four DSP units to perform real-time calculation, and includes hardware for developing the algorisms for hearing aids. As the ability of one DSP improves very much these days, two DSPs at high speed (60 MFLOPS each) are used to build up compact hearing aid. And the software had fitted to new hardware. It proved to be able to reduce the volume of the hearing aid to 1/20 of research system. This size is small enough to place to the sides of a telephone. In the last part of this project, much improvement in DSP performance was reported, and one DSP hearing aid for telephonic speech can be developed for the field test of SRA type hearing aid near future. And the fitting programs also should be improved for practical tests by hearing impaired person.