Drill-induced noise level during cochleostomy

Abstract

Conclusions: Noise induced by drilling during cochleostomy is of high level and can cause acoustic trauma to the inner ear, particularly after the membranous labyrinth has been exposed. Our method utilizes non-invasive noise measurement and the equipment that is connected to the operative area can be sterilized, thus it can be applied to intraoperative recordings. Objectives: To investigate the noise level generated by otological electrical drills during the cochleostomy procedure and to further explore the feasibility of noise monitoring in vivo. Methods: Acoustic measurements during drilling on the promontory of cochleae were carried out on 16 human cadavers (19 ears) using an ER7C probe microphone system. Results: The peak noise level generated during cochleostomy differed obviously from specimen to specimen and ranged from 85.9 to 131.5 dB SPL. We found three cases in which the peak noise level exceeded 130 dB SPL when the running burr touched the endosteal membrane.

Keywords::

• Acoustic trauma
• noise-induced hearing loss
• ER7C
• cochlear implantation
• inner ear

Acknowledgments

This research project was supported by the Karolinska Institute, Tysta Skolan, Stockholm County Council (ALF-funding), Sweden and Anhui Medical University, Xi’an Jiaotong University, Jilin University, China.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.