Mcleod Robert W J, Culling John F
School of Psychology, Cardiff University, Tower Building, Park Place, Cardiff, CF10 3AT, United Kingdom.
J Acoust Soc Am. 2017 May;141(5):3421. doi: 10.1121/1.4983471.
Bone-anchored hearing aids are a widely used method of treating conductive hearing loss, but the benefit of bilateral implantation is limited due to interaural cross-talk. The present study measured the phase and level of pure tones reaching each cochlea from a single, mastoid placed bone transducer on normal hearing participants. In principle, the technique could be used to implement a cross-talk cancellation system in those with bilateral bone conductors. The phase and level of probe tones over two insert earphones was adjusted until they canceled sound from a bone transducer (i.e., resulting in perceived silence). Testing was performed in 50-Hz steps between 0.25 and 8 kHz. Probe phase and level results were used to calculate inter-cochlear level and phase differences. The inter-cochlear phase differences of the bone-conducted sound were similar for all three participants showing a relatively linear increase between 4 and 8 kHz. The attenuation characteristics were highly variable over the frequency range as well as between participants. This variability was thought to be related to differences in skull dynamics across the ears. Repeated measurements of cancellation phase and level of the same frequency produced good consistency across sessions from the same participant.
骨锚式助听器是治疗传导性听力损失的一种广泛应用的方法，但由于双耳串扰，双侧植入的益处有限。本研究测量了正常听力参与者中，来自单个置于乳突的骨传导换能器到达每个耳蜗的纯音的相位和电平。原则上，该技术可用于为双侧骨传导器使用者实现串扰消除系统。调整两个插入式耳机上探测音的相位和电平，直到它们抵消来自骨传导换能器的声音（即，导致感觉安静）。在0.25至8kHz之间以50Hz步长进行测试。探测音的相位和电平结果用于计算耳蜗间的电平差异和相位差异。三名参与者的骨传导声音的耳蜗间相位差异相似，在4至8kHz之间呈现相对线性的增加。衰减特性在频率范围内以及参与者之间变化很大。这种变异性被认为与双耳颅骨动力学差异有关。对同一频率的抵消相位和电平进行重复测量，同一参与者在不同测试环节中产生了良好的一致性。
