"Two Ears Are Better Than One": Towards the Development of a Real-Time Crosstalk Cancellation System Based on Bone Conduction

对于那些耳朵有问题的人，不能从常规的空气传导助听器中受益，骨传导助听器是一个有价值的选择。然而，当“串音”发生时，本应由一只耳朵发出的声音无意中通过骨传导（BC）传到了另一只耳朵。这种不希望的声音传输会限制使用两个这样的设备的双耳优势。我们的项目旨在开发一个基于bc的相声消除系统，以改善双耳聆听体验。在2022年，我们重点研究了以下几个方面：(1)识别有效的耳内传感器来消除串音：我们评估了使用纯音听力阈值对耳蜗级消除贡献最大的耳内传感器，有和没有串音消除。我们的研究结果表明，使用探针麦克风可以获得更好的效果。(2)检查传感器放置对消除成功的影响：我们探索了耳道（探头麦克风）和乳突（加速度计）的位置。靠近内耳的传感器放置效果更好。(3)确定消除的最佳声音频率范围：由于难以接近，我们针对传感器而不是耳蜗进行串扰消除。耳蜗仍然可以消除声音，但只有在低频时才有效。(4)开发实时单边串音消除原型：我们在贝拉迷你音频平台上实现了我们的方法，使用简单的GUI实现了消除。我们的系统以低延迟实时运行。一个演示视频可以在https://youtu.be/D-Oy1AyythQ上找到

For those with ear issues unable to benefit from regular air conduction hearing aids, bone conduction-based hearing aids serve as a valuable alternative. However, when "crosstalk" occurs, sound intended for one ear inadvertently reaches the opposite ear through bone conduction (BC). This undesired sound transmission can limit the binaural advantages of using two such devices. Our project aims to develop a BC-based crosstalk cancellation system that improves binaural listening experiences. In 2022, we focused on the following aspects:(1) Identifying effective in-ear sensors for crosstalk cancellation: We assessed in-ear sensors contributing most to cochlear-level cancellation using pure-tone hearing thresholds, with and without crosstalk cancellation. Our findings revealed that using a probe microphone provided better results.(2) Examining sensor placements' impact on cancellation success: We explored the ear canal (probe microphone) and mastoid (accelerometer) locations. Sensor placement closer to the inner ear resulted in better perceived cancellation.(3) Determining optimal sound frequency range for cancellation: We targeted crosstalk cancellation at the sensor, not the cochlea, due to inaccessibility. The cancellation still reached the cochlea, but proved effective only at low frequencies.(4) Developing a real-time unilateral crosstalk cancellation prototype: We implemented our method on the Bela Mini Audio Platform, with a simple GUI enabling cancellation. Our system operated in real-time with low latency. A demo video is available online at https://youtu.be/D-Oy1AyythQ