Geal-Dor Miriam, Adelman Cahtia, Chordekar Shai, Sohmer Haim
Speech & Hearing Center, Hebrew University-Hadassah Medical Center, Jerusalem 91200, Israel.
Department of Communication Disorders, Hadassah Academic College, Jerusalem 91200, Israel.
Audiol Res. 2020 Dec 4;10(2):69-76. doi: 10.3390/audiolres10020012.
To gain insight into the broader implications of the occlusion effect (OE-difference between unoccluded and occluded external canal thresholds), the OE in response to pure tones at 0.5, 1.0, 2.0 and 4.0 kHz to two bone conduction sites (mastoid and forehead) and two soft tissue conduction (STC) sites (under the chin and at the neck) were assessed. The OE was present at the soft tissue sites and at the bone conduction sites, with no statistical difference between them. The OE was significantly greater at lower frequencies, and negligible at higher frequencies. It seems that the vibrations induced in the soft tissues (STC) during stimulation at the soft tissue sites are conducted not only to the inner ear and elicit hearing, but also reach the walls of the external canal and initiate air pressures in the occluded canal which drive the tympanic membrane and excite the inner ear, leading to hearing. Use of a stethoscope by the internist to hear intrinsic body sounds (heartbeat, blood flow) serves as a clear demonstration of STC and its relation to hearing.
为深入了解堵耳效应（OE，即未堵塞和堵塞外耳道阈值之间的差异）的更广泛影响，评估了在0.5、1.0、2.0和4.0kHz纯音刺激下，两个骨传导部位（乳突和前额）以及两个软组织传导（STC）部位（下巴下方和颈部）的OE。软组织部位和骨传导部位均存在堵耳效应，且二者无统计学差异。低频时堵耳效应显著更大，高频时可忽略不计。似乎在软组织部位刺激期间在软组织（STC）中诱发的振动不仅传导至内耳并引发听力，还到达外耳道壁并在堵塞的耳道中引发气压，从而驱动鼓膜并刺激内耳，进而导致听力。内科医生使用听诊器来聆听身体内部声音（心跳、血流），这清楚地证明了软组织传导及其与听力的关系。
