Institute of Biomedical Engineering Research, Kyungpook National University, Daegu, 41944, Korea.
Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA.
Sci Rep. 2021 Aug 18;11(1):16775. doi: 10.1038/s41598-021-95456-y.
Acoustic hearing aids generate amplified sound in the ear canal, and they are the standard of care for patients with mild to moderate sensorineural hearing loss. However, because of their limited frequency bandwidth, gain, and feedback, there is substantial room for improvement. Active middle ear implants, which directly vibrate the middle ear and cochlea, are an alternative approach to conventional acoustic hearing aids. They provide an opportunity to improve sound quality and speech understanding with amplification rehabilitation. For floating-mass type and direct-rod type (DRT) middle ear transducers, a differential floating-mass transducer (DFMT) and a tri-coil bellows transducer (TCBT), respectively, were fabricated to measure the output characteristics in four human temporal bones. Both were fabricated to have similar output forces per unit input and were placed in four human temporal bones to measure their output performances. The TCBT resulted in higher output than did the DFMT throughout the audible frequency range, and the output was more prominent at lower frequency ranges. In this study, we showed that DRT was a more effective method for round window stimulation. Because of its frequency characteristics and vibration efficiency, this implantation method can be utilized as a driving solution for middle ear implants.
声学助听器在耳道中产生放大的声音，是轻度至中度感音神经性听力损失患者的标准治疗方法。然而，由于其有限的频率带宽、增益和反馈，仍有很大的改进空间。主动中耳植入物直接振动中耳和耳蜗，是传统声学助听器的替代方法。它们为通过放大康复提高声音质量和言语理解提供了机会。对于浮体式和直接杆式（DRT）中耳换能器，分别制造了差动浮体换能器（DFMT）和三线圈波纹管换能器（TCBT），以测量四个人类颞骨中的输出特性。两者都被制造为具有相似的单位输入输出力，并被放置在四个人类颞骨中以测量它们的输出性能。在整个可听频率范围内，TCBT 的输出高于 DFMT，并且在较低的频率范围内输出更为突出。在这项研究中，我们表明 DRT 是刺激圆窗的更有效方法。由于其频率特性和振动效率，这种植入方法可以用作中耳植入物的驱动解决方案。
