When a transducer is placed on aural cartilage, relatively loud sound becomes audible in a conduction form termed cartilage conduction (CC). Previous studies have revealed the acoustical differences between CC and conventional air or bone conduction. This study elucidates the working principle of CC through measurements of threshold shifts by water injection into the ear canal under various fixation place conditions. Seven volunteers with normal hearing participated. A lightweight transducer was fixed for three CC conductions (on the tragus, antitragus, and intertragal incisure), and two non-CC conditions (on the pre-tragus and mastoid). Thresholds were measured at 500, 1000, and 2000 Hz in the 0%-, 40%-, and 80%-water injection conditions. Results for the three CC conditions revealed unique features different from those for the non-CC conditions. For the CC conditions, the thresholds increased by the 40%-water injection at all frequencies. However, with additional water injection (80%-water injection), the thresholds decreased at 500 and 1000 Hz; in particular, dramatically at 500 Hz. The results suggest that a direct vibration of the aural cartilage is important to obtaining the significant contribution of airborne sound to hearing above 1000 Hz. Fixation place results in no significant difference in acoustic features among CC conditions.

中文翻译：

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固定位置对软骨传导中空气传播声音的影响。

当将换能器放置在耳软骨上时，相对较大的声音会以称为软骨传导（CC）的传导形式被听到。先前的研究揭示了CC与传统的空气或骨骼传导之间的声学​​差异。这项研究通过测量在各种固定位置条件下注水入耳道的阈值偏移，阐明了CC的工作原理。七名听力正常的志愿者参加了会议。固定了一个轻巧的换能器，以进行三种CC传导（在耳屏，反耳屏和齿间刺激上）和两种非CC条件（在耳屏前和乳突上）。在注水0％，40％和80％的条件下，分别在500、1000和2000 Hz下测量阈值。三种CC条件的结果显示出与非CC条件不同的独特特征。对于CC条件，在所有频率下，注入40％的水都会增加阈值。但是，增加注水量（注水量为80％）后，阈值在500和1000 Hz时降低；特别是在500 Hz时。结果表明，耳软骨的直接振动对于获得空气声对1000 Hz以上的听力的重要贡献很重要。固定位置不会导致CC条件之间声学特征的明显差异。结果表明，耳软骨的直接振动对于获得空气声对1000 Hz以上的听力的重要贡献很重要。固定位置不会导致CC条件之间声学特征的明显差异。结果表明，耳软骨的直接振动对于获得空气声对1000 Hz以上的听力的重要贡献很重要。固定位置不会导致CC条件下声学特征的明显差异。