Active sound field control for sound reproduction in open ear canals

主动声场控制可在开放耳道中再现声音

• 批准号: 203315248
• 负责人: Professor Dr.-Ing. Matthias Blau
• 金额: --
• 依托单位: Institut für Hörtechnik und Audiologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/203315248?language=en
• 关键词: Active; sound; field; control; reproduction

Open-fitting hearing systems have proven to be efficient solutions for the rehabilitation of mild to moderate hearing loss. In comparison to closed-fitting systems, they are in particular much better accepted by the end user, most notably because they avoid the so-called occlusion effect. On the other hand, open-fitting hearing systems are technically challenging, because the effectively open ear canal makes them sensitive to noise penetrating from the Outside and to acoustic feedback from the receiver to the microphones. The current (passive) approach to optimally balance the suppression of occlusion, external noise and feedback is to carefully choose an appropriate vent size in combination with feedback cancellation algorithms. Alternatively, the upcoming availability of ear canal microphones in commercial hearing aids makes it possible to employ active approaches to tackle these different problems, and in addition derive an optimal individualized equalization of the sound pressure at the ear drum.The long-term objective of this project is to optimally exploit the availability of microphones and receivers in the ear canal or in the vent to develop improved individualized approaches for sound pressure equalization at the ear drum, for feedback cancellation and for noise reduction in open-fitting hearing devices.In the initial funding period, the focus was on individualized equalization, active noise reduction and individualized feedback cancellation for a hearing aid device equipped with one receiver and one ear canal microphone, where these problems were treated independently of each other and we considered time-invariant scenarios for the internal sound field. In the second funding period, we aim to extend the developed approaches to 1) dynamic scenarios for the internal sound field caused by changes ofthe ear canal geometry, and 2) hearing aid devices equipped with multiple receivers and microphones in the ear canal or in the vent, enabling to target feedback cancellation and equalization of the sound pressure at the ear drum simultaneously. This comprises both an adaptation of the individualized ear canal and feedback path models developed during the initial funding period, as well as the development of novel multi-loudspeaker-multi-microphone signal processing algorithms and acoustic models for combined feedback cancellation and equalization. In addition, measurement and evaluation procedures for dynamically varying feedback paths and acoustic ear canal impedances and real-time demonstrators of the individualized signal processing algorithms will be developed.Hence, this project contributes to all cardinal problems addressed by the Research Unit, namely the presentation problem using local approaches (feedback cancellation and equalization algorithms), the individualization problem (individualized ear canal and feedback path models), and the noise reduction problem.

开放式助听器已被证明是轻度至中度听力损失康复的有效解决方案。与封闭配合系统相比，它们特别地更好地被最终用户接受，最显著的是因为它们避免了所谓的闭塞效应。另一方面，开放式听力系统在技术上具有挑战性，因为有效开放的耳道使它们对从外部穿透的噪声以及从接收器到麦克风的声学反馈敏感。目前的（被动）方法，以最佳地平衡阻塞，外部噪声和反馈的抑制是仔细选择一个适当的排气口大小结合反馈消除算法。可替代地，在商业助听器中即将出现的耳道麦克风使得可以采用主动方法来解决这些不同的问题，并且另外导出鼓膜处的声压的最佳个性化均衡。本项目的长期目标是最佳地利用耳道或通风口中麦克风和接收器的可用性，以开发改进的个性化方法用于鼓膜处的声压均衡、反馈消除和开放式助听器的降噪。在最初的资助期间，重点是针对配备一个接收器和一个耳道麦克风的助听器设备的个性化均衡、主动降噪和个性化反馈消除，其中这些问题被彼此独立地处理，并且我们考虑了内部声场的时不变场景。在第二个资助期内，我们的目标是将开发的方法扩展到1）耳道几何形状变化引起的内部声场的动态场景，以及2）在耳道或通风口配备多个接收器和麦克风的助听器设备，从而能够同时实现反馈消除和鼓膜声压均衡。这包括在初始资助期间开发的个性化耳道和反馈路径模型的适应，以及用于组合反馈消除和均衡的新颖的多扬声器-多麦克风信号处理算法和声学模型的开发。此外，还将开发动态变化反馈路径和耳道声阻抗的测量和评估程序，以及个性化信号处理算法的实时演示程序。因此，本项目有助于研究部门解决的所有主要问题，即使用局部方法的呈现问题（反馈消除和均衡算法）、个性化问题（个性化耳道和反馈路径模型）和降噪问题。