Péus Dominik, Dobrev Ivo, Prochazka Lukas, Thoele Konrad, Dalbert Adrian, Boss Andreas, Newcomb Nicolas, Probst Rudolf, Röösli Christof, Sim Jae Hoon, Huber Alexander, Pfiffner Flurin
University of Zurich, University Hospital Zurich, Department of Otorhinolaryngology, Head and Neck Surgery, Frauenklinikstrasse 24, 8091, Zurich, Switzerland.
Institute of Fluid Dynamics, Swiss Federal Institute of Technology (ETHZ), Sonneggstrasse 3, 8092, Zurich, Switzerland; Streamwise GmbH, Emil-Staub-Strasse 5, 8708, Männedorf, Switzerland.
Hear Res. 2017 Aug;351:88-97. doi: 10.1016/j.heares.2017.06.002. Epub 2017 Jun 7.
Animals are frequently used for the development and testing of new hearing devices. Dimensions of the middle ear and cochlea differ significantly between humans and commonly used animals, such as rodents or cats. The sheep cochlea is anatomically more like the human cochlea in size and number of turns. This study investigated the middle-ear ossicular velocities and intracochlear sound pressure (ICSP) in sheep temporal bones, with the aim of characterizing the sheep as an experimental model for implantable hearing devices. Measurements were made on fresh sheep temporal bones. Velocity responses of the middle ear ossicles at the umbo, long process of the incus and stapes footplate were measured in the frequency range of 0.25-8 kHz using a laser Doppler vibrometer system. Results were normalized by the corresponding sound pressure level in the external ear canal (P). Sequentially, ICSPs at the scala vestibuli and tympani were then recorded with custom MEMS-based hydrophones, while presenting identical acoustic stimuli. The sheep middle ear transmitted most effectively around 4.8 kHz, with a maximum stapes velocity of 0.2 mm/s/Pa. At the same frequency, the ICSP measurements in the scala vestibuli and tympani showed the maximum gain relative to the P (24 dB and 5 dB, respectively). The greatest pressure difference across the cochlear partition occurred between 4 and 6 kHz. A comparison between the results of this study and human reference data showed middle-ear resonance and best cochlear sensitivity at higher frequencies in sheep. In summary, sheep can be an appropriate large animal model for research and development of implantable hearing devices.
动物经常被用于新型听力设备的研发和测试。人类与常用动物（如啮齿动物或猫）的中耳和耳蜗尺寸存在显著差异。绵羊的耳蜗在大小和匝数上在解剖学上更接近人类耳蜗。本研究调查了绵羊颞骨中的中耳听骨速度和耳蜗内声压（ICSP），旨在将绵羊表征为可植入听力设备的实验模型。对新鲜的绵羊颞骨进行了测量。使用激光多普勒振动计系统在0.25 - 8kHz频率范围内测量了中耳听骨在鼓膜脐、砧骨长突和镫骨足板处的速度响应。结果通过外耳道中的相应声压级（P）进行归一化。随后，在施加相同声学刺激的同时，用基于定制MEMS的水听器记录前庭阶和鼓阶处的ICSP。绵羊中耳在约4.8kHz时传输最有效，镫骨最大速度为0.2mm/s/Pa。在相同频率下，前庭阶和鼓阶处的ICSP测量相对于P显示出最大增益（分别为24dB和5dB）。耳蜗隔板上最大的压力差出现在4至6kHz之间。本研究结果与人类参考数据的比较表明，绵羊中耳的共振和耳蜗最佳敏感性出现在更高频率。总之，绵羊可以成为可植入听力设备研发的合适大型动物模型。
