助聽器晶片及系統---子計畫二：助聽器聲學系統設計(I)

Abstract

高階的助聽器系統應具有大量的訊號處理功能，例如適應性指向麥克風、雜訊消除、回音消除等，以提升舒適感和實用性。欲達成這些前瞻的功能、除了借鏡既有的訊號處理方法，亦必須結合對人類聽覺特性的瞭解以及助聽器應用場合特殊的聲響狀況，方能發展最佳化的訊號處理策略。本研究計劃將以現實的人體聲學和環境聲學模型為基礎，對助聽器系統的訊號品質改進提出對策。主要工作項目如下：(1)建立耳道聲學測量數據，利用這些資料可為迴音路徑的探明以及最佳聲學制動器配置等問題提供基本資料。(2)優化適應性迴音消除演算法，實現低功率適應性迴音消除器。(3)建立雜訊分析模擬環境，以利評估各種噪音抑制策略，發展噪音抑制演算法。(4)發展人類聽覺模型(human perception model)衍生之語音強化技術。(5)整合迴音消除及噪音抑制方法於低功率數位訊號處理平台，配合完成助聽器原型製作。

The realization of high-end hearing aids heavily reply on the deployment of many signal processing functions, which include but are not limited to, adaptive directional microphones, noise cancellation, echo cancellation, etc. These functions are commonly regarded as crucial in promoting the comfort and effectiveness of hearing aid systems. Several existing signal processing techniques may be borrowed to implement these functions; however, to achieve these goals satisfactorily, a deeper understanding of human auditory perception and the application scenarios is a must for forging an optimal strategy of applying signal processing. In this project, it is intended to base our development on realistic human and environmental acoustic models, and to propose a comprehensive solution for the enhancement of sound quality in hearing aid systems. Main goals include the following: (1) Establish acoustic models and simulation platforms. Characterize the echo paths in hearing aid systems. (2) Optimize the echo-cancellation algorithm for ultra low-power echo cancellers. (3) Build a noise simulation environment to evaluate the effectiveness of various noise-reduction techniques. (4) Develop speech enhancement technologies based on human auditory perception models. (5) Implement the echo canceller and the noise reduction algorithm, integrate them into the SoC platform, and participate developing the hearing aid prototype.