Signal processing methods to address some challenges in binaural hearing aids

该提案旨在为实现下列长期目标采取重大步骤：1）提高助听器的性能和鲁棒性，并使听力残疾者更好地接受和使用助听器，以及2）使助听器以及通常的多通道语音/音频/声学处理系统对困难的、具有挑战性的现实生活声学环境（包括存在竞争性谈话者）具有鲁棒性，各种类型和水平的噪音和混响条件。为了实现这些目标的进展，提出了三个短期目标。在双耳助听器（以及其他应用）中，由于不完美的到达方向估计方案、助听器用户的头部运动和多径传播，假设用于处理的目标到达方向和实际目标到达方向之间可能存在失配或误差。这种不匹配会导致波束形成算法的显著性能下降，并且它今天仍然是一个重要的问题。本提案的第一个短期目标是开发用于双耳助听器的波束形成算法，该算法对估计的目标到达方向中的误差具有鲁棒性。通过无线链路的耳到耳通信是双耳助听器的另一个挑战，具有挑战性的音频编码规范包括低带宽、低延迟（小于1-2 ms）、低复杂度和宽带频谱。该提案的第二个短期目标包括开发用于双耳助听器的子带域后向线性预测音频编码方案。我们将添加新的噪声整形方案，包括来自双耳波束成形算法的白色噪声增益的实时反馈，以避免或减少波束成形算法的量化噪声放大。此外，考虑到所使用的后向线性预测编码方案的特定低延迟约束和编码器-解码器同步问题，将为低延迟子带编解码器开发自定义分组丢失隐藏方案。第三个短期目标涉及我们最近提出的用于双耳助听器波束成形的方案的进一步开发，这既可以降低噪声又可以保留背景噪声和竞争讲话者的双耳线索。我们将研究各种策略，以降低复杂性的方法，通过利用组件之间的冗余和选择组件，允许更好地共享资源。我们还将调查的算法，其中需要通过无线链路传输的信号的数量最小化的带宽效率的版本的发展。这些改进将显著提高实现所提出的方法的助听器的电池寿命。

The proposal aims to achieve significant steps towards the following long-term objectives: 1) To increase performance and robustness of hearing aids and achieve greater acceptance and usage by people with hearing disability, and 2) to make hearing aids and, in general, multichannel speech/audio/acoustics processing systems robust to difficult, challenging real-life acoustic environments, including the presence of competing talkers, of various types and levels of noise, and reverberant conditions. To achieve progress towards these objectives, three short-term objectives are proposed.In binaural hearing aids (and other applications as well), there can be a mismatch or an error between the target direction of arrival assumed for processing and the actual target direction of arrival, because of imperfect direction of arrival estimation schemes, small head movements from the hearing aid user, and multipath propagation. This mismatch can result in significant performance degradation in beamforming algorithms, and it is still an important problem today. The first short-term objective of this proposal is to develop beamforming algorithms for binaural hearing aids which are robust to errors in the estimated target direction of arrival.The ear-to-ear communication through a wireless link is another challenge in binaural hearing aids, with challenging specifications for the audio coding including low bandwidth, low delay (less than 1-2 ms), low complexity, and wideband spectrum. The second short-term objective of the proposal consists of developing a sub-band domain backward linear prediction audio coding scheme for binaural hearing aids. We will add a new noise shaping scheme including real-time feedback from the white noise gain of the binaural beamforming algorithm, to avoid or reduce quantization noise amplification by the beamforming algorithm. Moreover, a custom packet loss concealment scheme will be developed for the low-delay sub-band codec, considering the specific low-delay constraint and coder-decoder synchronization issues of the backward linear prediction coding scheme being used.The third short-term objective concerns the further development of a scheme that we recently proposed for binaural hearing aids beamforming, which can both reduce noise and preserve the binaural cues of the background noise and competing talkers. We will investigate various strategies to reduce the complexity of the method by exploiting redundancies between components and by choosing components that allow better sharing of resources. We will also investigate the development of bandwidth efficient versions of the algorithms, where the number of signals that need to be transmitted through a wireless link is minimized. These improvements will significantly improve the battery life of hearing aids implementing the proposed method.