Ishikawa Hiromu, Otsuka Sho, Nakagawa Seiji
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:3881-3884. doi: 10.1109/EMBC44109.2020.9176270.
Bone-conducted ultrasound (BCU) is perceived even by the profoundly sensorineural deaf and has been applied to the development of a novel hearing aid. In the BCU hearing aid, the vibrator is pressed onto the mastoid process of the temporal bone (the osseous bulge behind the ear). However, BCU can be heard on distal parts of the body; e.g., the muscle of the neck, the clavicle and the upper limbs. Some studies have been carried out to develop other BCU hearing devices using this "distant presentation". However, the possibility of the localization of distantly-presented BCU has not been verified. In this study, we investigated whether listeners could use the interaural time differences (ITDs) and intensity differences (IIDs) as cues for lateralization (left/right discrimination) of distantly-presented BCU. The results showed that lateralization based on ITDs and IIDs is possible to some extent, even for the distant presentation, whereas lateralization become difficult as the stimulus placement gets further from the head. Lateralization based on IIDs was more accurate than that based on ITDs. IIDs seem to give more effective cues than ITDs in the lateralization of BCU.
即使是极重度感音神经性聋患者也能感知骨传导超声（BCU），并且骨传导超声已被应用于新型助听器的研发。在骨传导超声助听器中，振动器被按压在颞骨的乳突上（耳朵后方的骨性隆起）。然而，在身体的远端部位也能听到骨传导超声，例如颈部肌肉、锁骨和上肢。已经开展了一些研究，以利用这种“远距离呈现”来开发其他骨传导超声听力设备。然而，远距离呈现的骨传导超声的定位可能性尚未得到验证。在本研究中，我们调查了听众是否可以将双耳时间差（ITD）和强度差（IID）用作远距离呈现的骨传导超声的定位线索（辨别左右）。结果表明，即使对于远距离呈现，基于双耳时间差和强度差的定位在一定程度上也是可行的，然而，随着刺激部位离头部越来越远，定位变得困难。基于强度差的定位比基于双耳时间差的定位更准确。在骨传导超声的定位中，强度差似乎比双耳时间差提供了更有效的线索。
