School of Psychology, Cardiff University, Tower Building, Park Place, Cardiff CF10 3AT, United Kingdom.
J Acoust Soc Am. 2019 Nov;146(5):3295. doi: 10.1121/1.5131650.
Two bone-conduction hearing aids (BCHAs) could deliver improved stereo separation using cross-talk cancellation. Sound vibrations from each BCHA would be cancelled at the contralateral cochlea by an out-of-phase signal of the same level from the ipsilateral BCHA. A method to measure the level and phase required for these cancellation signals was developed and cross-validated with an established technique that combines air- and bone-conducted sound. Three participants with normal hearing wore bone transducers (BTs) on each mastoid and insert earphones. Both BTs produced a pure tone and the level and phase were adjusted in the right BT in order to cancel all perceived sound at that ear. To cross-validate, one BT was stimulated with a pure tone and participants cancelled the resultant signal at both cochleae via adjustment of the phase and level of signals from the earphones. Participants achieved cancellation using both methods between 1.5 and 8 kHz. Levels measured with each method differed by <1 dB between 3 and 5 kHz. The phase results also corresponded well for the cancelled ear (11° mean difference) but poorly for the contralateral ear (38.4° mean difference). The first method is transferable to patients with middle-ear dysfunction, but covers a limited frequency range.
两个骨导助听器 (BCHA) 可以通过串扰消除来提供更好的立体声分离。每个 BCHA 的声音振动将通过来自对侧 BCHA 的同相水平的反相信号在对侧耳蜗中被消除。开发了一种测量这些消除信号所需的水平和相位的方法，并与结合空气和骨传导声音的现有技术进行了交叉验证。三名听力正常的参与者在每个乳突上佩戴骨导换能器 (BT)，并插入耳机。两个 BT 都产生纯音，并且在右 BT 中调整水平和相位以消除该耳听到的所有声音。为了交叉验证，一个 BT 被纯音刺激，参与者通过调整耳机信号的相位和水平来消除两个耳蜗的信号。参与者使用这两种方法在 1.5 和 8 kHz 之间实现了消除。两种方法在 3 至 5 kHz 之间的测量水平差异小于 1 dB。对于被消除的耳朵，相位结果也非常匹配（平均差异 11°），但对于对侧耳朵则不匹配（平均差异 38.4°）。第一种方法可用于中耳功能障碍的患者，但覆盖的频率范围有限。
