Noise Exposure of the Inner Ear During Drilling a Cochleostomy for Cochlear Implantation

Abstract

In the drilling procedure for a cochleostomy, the inner ear may be affected by very high SPLs, particularly if the endosteal membrane is left intact and comes into contact with the running burr. Of course, the resulting SPLs depend on the drilling speed and the size and characteristics of the burr (larger burrs cause higher SPLs); however, we are of the opinion that the cochlear function is at risk, anyway, if special precaution is not exercised. Even when working with reduced drilling speed, the surgeon should be aware of the high risk in the form of an acoustic trauma, which may endanger residual hearing. Recommendations in terms of "soft surgery" are given in the paper (e.g., the use of microhooks instead of a drill to remove the very last shell of bone covering the cochlea).