Influence of drilling on the distortion product otoacoustic emissions in the non-operated ear.
OBJECTIVE
To determine possible changes in the outer hair cell (OHC) function related to drill noise exposure.


METHODS
Distortion product otoacoustic emissions (DPOAE) were measured at frequencies of f(2) = 2, 3, 4 and 5 kHz, and a frequency ratio f(1)/f(2) = 1.22. The f(1) and f(2) levels were delivered at 65 dB SPL. DPOAE amplitudes were compared in 13 patients both before and after mastoidectomy, and between these patients and 5 patients who underwent tympanoplasty.


RESULTS
The DPOAE amplitudes were significantly decreased at 2 and 4 kHz (p = 0.01 and p = 0.013, respectively) immediately after the mastoidectomy, and still differed from the preoperative results at these frequencies on the first post-mastoidectomy day. After the various individual fluctuations, the DPOAE amplitudes remained decreased in some of the patients at the end of the study.


CONCLUSIONS
Drill-induced noise during mastoidectomy can cause reversible changes in DPOAE in the non-operated ear. OHC function may be diminished during the period after mastoid surgery, and last >1 month.
Migirov
Lela
L
Department of Otolaryngology Head and Neck Surgery, Sheba Medical Center (affiliated to Sackler School of Medicine), Tel Aviv University, Tel Aviv, Israel. sabim@bezeqint.net
Wolf
Michael
M
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D018072:Hair Cells, Auditory, Outer / Q000502:physiology*; D034381:Hearing Loss / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology*; D008297:Male; D008416:Mastoid / Q000601:surgery; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D017084:Otoacoustic Emissions, Spontaneous; D011446:Prospective Studies; D020127:Recovery of Function; D013525:Surgical Instruments; D014433:Tympanoplasty / Q000009:adverse effects* / Q000379:methods; D014732:Vibration; D055815:Young Adult