A Study on Utility and improvement of Sensory Substitute Devices for Education Engineering of the Hearing Impaired.

1. 为了提高聋人指尖触觉声码器对辅音的识别能力，提出了一种新的振动模式显示方法。(1)心理物理实验发现，辅音部分不像元音那么容易被识别的原因之一是时间掩蔽。为解决上述问题，利用16排小振子矩阵，以扫描方式在指尖上显示语音频谱模式。(2)在指尖扫过两个振动点的同时，在不同条件下测量两点阈值。通过实验得出了最佳扫频速度。结果表明，使用最佳扫描速度可以避免元音对辅音部分的时间屏蔽。为聋儿和儿童设计了一种新型的耳蜗外假体。(1)我们开发了一种涂有聚乙烯醇凝胶的Pt-Ir电极，其中含有生理盐水溶液。涂层电极可以牢固地附着在圆窗膜上而不造成损伤，使患者的残余听力不会丧失，因此适用于耳蜗外假体。(2)在我们的遥测方法中，语音处理器的输出通过电磁耦合从耳模内的第一线圈传输到植入外耳皮肤下的第二线圈。使用这种方法，受试者只需要接受一个非常小的手术。我们的人工耳蜗甚至可以应用于小孩子。(3)作为语音编码方法。提出了一种通过电极同时传输基音信号和第二形成峰频率的新方法。使用数字信号处理器检测基音信号和第二形成峰频率大约需要20毫秒。通过简单的测试，这种新的语音编码方法已经被证明是有效的，可以识别出五个日语元音。

1. A new display method of vibration patterns was proposed in order to improve the recognition of consonants by our fingertip tactile vocoder for the deaf.(1) One of the reasons why consonant parts could not be so much recognized as vowels was found to be caused by temporal masking based on psychophysical experiments. To solve the above problem, the speech spectrum patterns were displayed on a fingertip with swept mode using a small vibrator matrix with 16 rows.(2) Two-point thresholds were measured in the various conditions while sweeping two vibrating points on a fingertip. The optimal swept speed was obtained from the experiments. It was ascertained that the temporal masking of consonant parts by vowels could be avoided by using the optimal swept speed.2. A new model of an extracochlear prosthesis has been designed for deaf infants and children.(1) We have developed a Pt-Ir electrode coated with polyvinyl alcohol gel which contains a saline solution. The coated electrode is suitable for the extracochlear prosthesis because it can firmly adhere to the round window membrane without causing damage so that the residual hearing of patients may not be lost.(2) In our telemetry method, the output of the speech processor is transmitted with electromagnetic coupling from the first coil inside the earmold to the second coil implanted under the skin of an external ear. Using this method, the subject only has to receive a very minor operation. Our cochlear prosthesis may possibly be applied to even a small child.(3) As a speech coding method. a new idea has been proposed to simultaneously transmit the pitch signal and the second formant frequency through an electrode. It took about 20 ms to detect the pitch signal and the second formant frequency by using a digital signal processor. This new method of speech coding has proven effective for discrimination of the five Japanese vowels based on simple tests.