ENT Department, University Basel Hospital, Basel, Switzerland.
Business Unit Vibrant, MED-EL, Innsbruck, Austria.
Int J Audiol. 2023 Feb;62(2):192-198. doi: 10.1080/14992027.2022.2031317. Epub 2022 Feb 17.
The Vibrant Soundbridge (VSB) is one of the most widely used implantable hearing devices. It consists of a vibrating floating mass transducer (FMT) that is connected to a middle ear structure. The standard coupling devices for sensorineural hearing loss are short process (SP) or long process (LP) couplers.
This study directly compared the electro-mechanical performance of the SP- and LP-coupled FMT of the VSB in the same temporal bone specimen (= 10). We measured velocity magnitudes and total harmonic distortions (THD) of the stapes (ST) and the round window (RW) using laser Doppler Vibrometry (LDV).
Comparison shows a maximally 10 dB higher magnitude for the LP coupler at ST and RW for frequencies below 600 Hz, whereas the SP coupler shows a maximally 20 dB higher magnitude at the ST and RW for frequencies above 600 Hz. THD show similar behaviour with less distortion at 500 Hz for the LP coupler and less distortions for the SP coupler in higher frequencies.
Our experiments showed that the SP coupling may be mechanically favourable, in terms of magnitude and distortion, for the transmission of FMT vibrations at higher frequencies.
Vibrant Soundbridge（VSB）是应用最广泛的植入式听力设备之一。它由一个与中耳结构相连的振动式浮动质量换能器（FMT）组成。用于感音神经性听力损失的标准耦合装置是短突（SP）或长突（LP）耦合器。
本研究在同一颞骨标本（n=10）中直接比较了 VSB 的 SP 和 LP 耦合 FMT 的机电性能。我们使用激光多普勒测振仪（LDV）测量了镫骨（ST）和圆窗（RW）的速度幅度和总谐波失真（THD）。
比较显示，在低于 600Hz 的频率下，LP 耦合器在 ST 和 RW 的幅度最大可高出 10dB，而在高于 600Hz 的频率下，SP 耦合器在 ST 和 RW 的幅度最大可高出 20dB。THD 也表现出类似的行为，LP 耦合器在 500Hz 时失真较小，而 SP 耦合器在较高频率时失真较小。
我们的实验表明，在传递 FMT 振动方面，SP 耦合在较高频率下可能在幅度和失真方面具有机械优势。
