Methods: The study included 42 ears of 21 patients (11 males, 10 females; mean age 61 years; range 44 to 76 years) who underwent coronary artery bypass grafting. None of the patients had a history of cerebrovascular disease such as ischemic cerebrovascular event, syncope, or hearing loss. The number of arteries bypassed ranged from 1 to 4 (mean 2.7). The patients were examined with pure tone audiometry, speech discrimination test, and tympanometry, and transiently evoked (TEOAE) and distortion product (DPOAE) otoacoustic emissions were recorded preoperatively and on the postoperative sixth day. The pure tones were obtained at the frequencies of 250, 500, 1,000, 2,000, 4,000, and 6,000 Hz.

Results: None of the patients had hearing loss or sudden deafness after surgery. Preoperative and postoperative pure tone results of the patients did not differ significantly (p>0.05). The mean pre- and postoperative speech discrimination scores were 88±14% and 91±1%, respectively (p<0.05). Pre- and postoperative DPOAE findings did not differ significantly (p>0.05). Audiometric results showed no correlations with the number of bypassed arteries and operative variables (p>0.05).

Conclusion: Our findings suggest that coronary artery bypass grafting with extracorporeal circulation does not impose a risk for hearing loss and for the functions of outer hair cells in the inner ear.