Division of Neurotology and Skull Base Surgery, Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine, California 92868, USA.
Otol Neurotol. 2013 Jan;34(1):115-20. doi: 10.1097/MAO.0b013e318278522e.
Whether a prototype direct-drive hearing device (DHD) is effective in driving the tympanic membrane (TM) in a temporal bone specimen to enable it to potentially treat moderate-to-severe hearing loss.
Patient satisfaction with air conduction hearing aids has been low because of sound distortion, occlusion effect, and feedback issues. Implantable hearing aids provide a higher quality sound but require surgery for placement. The DHD was designed to combine the ability of driving the ossicular chain with placement in the external auditory canal.
DHD is a 3.5-mm wide device that could fit entirely into the bony ear canal and directly drive the TM rather than use a speaker. A cadaveric temporal bone was prepared. The device developed in our laboratory was coupled to the external surface of the TM and against the malleus. Frequency sweeps between 300 Hz to 12 kHz were performed in 2 different coupling methods at 104 and 120 dB, and the DHD was driven with various levels of current. Displacements of the posterior crus of the stapes were measured using a laser Doppler vibrometer.
The DHD showed a linear frequency response from 300 Hz to 12 kHz. Placement against the malleus showed higher amplitudes and lower power requirements than when the device was placed on the TM.
DHD is a small completely-in-the-canal device that mechanically drives the TM. This novel device has a frequency output wider than most air conduction devices. Findings of the current study demonstrated that the DHD had the potential of being incorporated into a hearing aid in the future.
一种原型直接驱动听力设备（DHD）是否能有效地驱动颞骨标本中的鼓膜（TM），从而有可能治疗中重度听力损失。
由于声音失真、闭塞效应和反馈问题，患者对空气传导助听器的满意度一直很低。植入式助听器提供更高质量的声音，但需要手术放置。DHD 的设计目的是将驱动听骨链的能力与放置在外耳道内的能力结合起来。
DHD 是一种 3.5 毫米宽的设备，可以完全放入骨性耳道内，直接驱动 TM，而不是使用扬声器。准备了一具尸体颞骨。我们实验室开发的设备与 TM 的外表面耦合，并与锤骨接触。在 104 和 120dB 的两种不同耦合方法下，在 300Hz 到 12kHz 的频率范围内进行了扫频，并用不同水平的电流驱动 DHD。使用激光多普勒测振仪测量了镫骨后脚的位移。
DHD 在 300Hz 到 12kHz 的频率范围内表现出线性响应。与锤骨接触的位置显示出比将设备放置在 TM 上更高的振幅和更低的功率要求。
DHD 是一种完全在耳道内的小型设备，它通过机械驱动 TM。这种新型设备的频率输出范围比大多数空气传导设备更宽。当前研究的结果表明，DHD 有可能在未来被纳入助听器。
