title: An in vitro study of mechanical heart valve sound loudness.
abstract: The purpose of the study was to measure the valve sound loudness of eight 25 mm aortic mechanical heart valve prostheses under controlled laboratory conditions in an isolated acoustic environment. A specially designed single-chamber pulse duplicator was constructed within an anechoic box that isolated the sounds of the valve from external noise. The valves were closed with a stimulated aortic pressure waveform of three different amplitudes. Valve sound loudness was measured with ISO-532/B (Zwicker method), which is based on a model of loudness perception that is better than dB(A), the traditional A-weighted sound pressure level. The average loudness for each valve was St. Jude Medical, 0.97 sones; CarboMedics, 0.98 sones; Sorin Biomedica Bicarbon, 1.08 sones; Edwards Tekna, 1.92 sones; Edwards Duromedics, 2.36 sones; Monostrut, 2.48 sones; Sorin Biomedica Carbocast, 3.17 sones; and Medtronic Hall, 3.57 sones. There was a positive trend between valve sound loudness and aortic drive pressure for most valves in the study.
authors.affiliation: CarboMedics, Inc., Austin, Texas 78752.
authors.forename: R L
authors.initials: RL
authors.lastname: Erickson
authors.forename: L I
authors.initials: LI
authors.lastname: Thulin
authors.forename: G J
authors.initials: GJ
authors.lastname: Richard
mesh_terms: D001021:Aortic Valve; D004780:Environment, Controlled; D006350:Heart Valve Prosthesis; D006801:Humans; D011312:Pressure; D013016:Sound