Effect of mastoid drilling on the distortion product otoacoustic emissions in the non operated ear

Objective To monitor the effect of mastoid drilling on the non-operated ear distortion product otoacoustic emissions. Materials and methods Distortion product otoacoustic emissions (DPOAEs) were measured at frequencies of f 2 = 2, 3, 4 and 5 kHz, and a frequency ratio f 1 /f 2 = 1.22. DPOAEs were measured in 49 cases, pre and post-operatively who underwent mastoid drilling procedures, compared with each other and with 49 controls who underwent myringoplasty and myringotomy procedures. Results Amplitudes of DPOAEs decreased significantly in those who underwent mastoidectomies over all the measured frequencies in the immediate post-operative period but had recovered by the seventh post operative day. Conclusion Drill induced noise can cause temporary decrease in the DPOAEs postoperatively and hence temporary hearing loss for a period of one week.