A trial of designing phoneme-enhancing and noise-suppressing directive hearing aid with the aim of auditory support for presbyacusic listeners

我们提出了一种自适应数字滤波器，它可以增强共振峰的过渡和辅音的带噪声，从而提高发音分数。详情如下。首先，为了增强辅音的形成峰转换，我们事先制作了频率特征与人类听觉滤波器相匹配的带通滤波器。采用适合辅音声学特征的采样频率和采样间隔对声音信号进行编码。利用选择性线性预测编码估计频谱位置，选择覆盖频谱局部峰带宽的带通滤波器。对增强辅音进行了发音测试，结果表明，增强了共振峰的编辑辅音明显改善了发音。其次，提出了一种新的算法来检测带有带噪声的辅音，如摩擦音。声音信号被分离到四个带通滤波器中，每个带通滤波器的振幅被计算为检测的声信号。结果，摩擦辅音被检测与三个触发输出从带通滤波器。

We propose an adaptive digital filter which enhances transition of formants and band noise in consonants, so as to improve the articulation scores. The details are presented below.First, for enhancement of the formant transition of consonants, we beforehand generated band-pass filters whose characteristics of frequency match the human auditory filters. Sound signals were encoded by the sampling frequency and interval which were fit for acoustic features of consonants. Spectrum loci was estimated by selective linear predictive coding in order to select the band-pass filters which cover the band width of the local peaks of spectrum. The articulation test to enhanced consonants was carried out, which became evident that the editted consonants which have enhanced formant peaks improved the articulation.Second, a new algorithm was proposed to detect the consonants which have band noise as an acoustic feature, such as a fricative sound. Sound signals were separated into four band-pass filters, from which each amplitudes were calculated as acoustic cues for the detection. As a result, the fricative consonants were detected with three trigger outputs from the band-pass filters.