Geal-Dor Miriam, Sohmer Haim
Speech & Hearing Center, Hebrew University-Hadassah Medical School, Jerusalem 91200, Israel.
Department of Communication Disorders, Hadassah Academic College, Jerusalem 91200, Israel.
Audiol Res. 2021 Jul 9;11(3):335-341. doi: 10.3390/audiolres11030031.
Soft tissue conduction is an additional mode of auditory stimulation which can be initiated either by applying an external vibrator to skin sites not overlying skull bone such as the neck (so it is not bone conduction) or by intrinsic body vibrations resulting, for example, from the heartbeat and vocalization. The soft tissue vibrations thereby induced are conducted by the soft tissues to all parts of the body, including the walls of the external auditory canal. In order for soft tissue conduction to elicit hearing, the soft tissue vibrations which are induced must penetrate into the cochlea in order to excite the inner ear hair cells and auditory nerve fibers. This final stage can be achieved either by an osseous bone conduction mechanism, or, more likely, by the occlusion effect: the vibrations of the walls of the occluded canal induce air pressures in the canal which drive the tympanic membrane and middle ear ossicles and activate the inner ear, acting by means of a more air conduction-like mechanism. In fact, when the clinician applies his stethoscope to the body surface of his patient in order to detect heart sounds or pulmonary air flow, he is detecting soft tissue vibrations.
软组织传导是一种额外的听觉刺激模式，它可以通过以下两种方式启动：一是将外部振动器应用于颈部等未覆盖颅骨的皮肤部位（因此不是骨传导），二是由身体内部的振动引起，例如心跳和发声。由此产生的软组织振动通过软组织传导到身体的各个部位，包括外耳道壁。为了使软组织传导引发听觉，所诱导的软组织振动必须穿透到耳蜗中，以激发内耳毛细胞和听神经纤维。这最后一个阶段可以通过骨传导机制实现，或者更有可能是通过堵塞效应实现：被堵塞耳道壁的振动会在耳道内产生气压，从而驱动鼓膜和中耳听小骨，并激活内耳，其作用方式更类似于气传导机制。事实上，当临床医生将听诊器应用于患者体表以检测心音或肺气流时，他检测的就是软组织振动。
