Assessment of Perceived Mechanical Heart Valve Sound Level in Patients
Hans Nygaard DMSC,, Peter Johansen BSc, Carsten Riis BSc,
J. Michael Hasenkam MD, Peter K. Paulsen MD

The study aim was to quantitate what patients perceive as sound from their mechanical heart valve prostheses, including air-transmitted sound waves and bone-transmitted vibrations. Thirty-four patients with implanted mechanical bileaflet aortic and mitral valves were included. Closing sounds measured by an accelerometer on the patients' chest were delayed 400 ms, amplified and played back to the patient through the loudspeaker. The patient adjusted the feedback sound to the same level as the 'real-time' clicks he/she perceived directly from their valve. In this way the feedback sound energy includes both the air- and bone-transmitted energies. The mean air-transmitted sound pressure level (SPL) measured close to the patient's ear was 23 ± 4 dB(A). The total air- and bone-transmitted sounds and vibrations were perceived by the patients as a SPL of 34 ± 5 dB(A). Patients with implanted mechanical heart valve prostheses seem to perceive the sound from their valve two to four times higher than nearby persons, because of the additional bone-transmitted vibrations.

The study aim was to quantitate what patients perceive as sound from their mechanical heart valve prostheses, including air-transmitted sound waves and bone-transmitted vibrations. Thirty-four patients with implanted mechanical bileaflet aortic and mitral valves were included. Closing sounds measured by an accelerometer on the patients' chest were delayed 400 ms, amplified and played back to the patient through the loudspeaker. The patient adjusted the feedback sound to the same level as the 'real-time' clicks he/she perceived directly from their valve. In this way the feedback sound energy includes both the air- and bone-transmitted energies. The mean air-transmitted sound pressure level (SPL) measured close to the patient's ear was 23 ± 4 dB(A). The total air- and bone-transmitted sounds and vibrations were perceived by the patients as a SPL of 34 ± 5 dB(A). Patients with implanted mechanical heart valve prostheses seem to perceive the sound from their valve two to four times higher than nearby persons, because of the additional bone-transmitted vibrations.