BACKGROUND: The "click" sound of mechanical heart valve prostheses has been recognized as a disturbing factor for some patients after mechanical heart valve implantation. The factors determining the extent of disturbance remain controversial.

METHODS: Ninety-five unmatched patients with six different valve types were examined (Duromedics-Edwards, Björk-Shiley, St. Jude Medical, Medtronic, CarboMedics, and Omnicarbon), including 12 patients with double-valve replacement. Three groups (Björk-Shiley, Duromedics-Edwards, and St. Jude Medical) were comparable in size. All patients were examined and interviewed, a hearing test was performed, and valve sounds were analyzed. Sound transmission was evaluated.

RESULTS: The loudest valve was the Duromedics-Edwards prosthesis (mean, 84.2 dB[A] impulse) and the St. Jude Medical was the quietest (mean, 73.5 dB[A] impulse). This ranking was independent of patient variables and valve position. Discomfort level correlated with hearing loss and loudness of the valve. Patients desiring a quieter valve had better hearing, had louder valve sounds, felt disturbed by the sound, had partners who felt disturbed, and were receiving coumarin for anticoagulation. Sound was transmitted predominantly by air conduction. The frequency analysis to identify different valves was unsatisfactory, but louder frequencies did correspond with hearing-impaired patients' audiograms.

CONCLUSIONS: Our results emphasize the need for valve design changes, preoperative education about the sound, and inclusion of routine hearing tests into the preoperative workup.