Modeling impermeable membranes as acoustic filters for biomedical applications

The main purpose of this research project was to explore a mathematical expression that could be used by medical device designers to appropriately select impermeable membranes to isolate acoustic transducers from water, dust, earwax or other foreign material. The sound transmission properties of various types of impermeable membranes were analytically evaluated and compared to experimental measurements. Computer simulations were also performed to estimate the effects of three key membrane parameters: thickness (h), density (p) and sound speed (c), on the membrane's overall acoustic response. Results indicated that membrane thickness and density affect sound transmission the most. Membrane sound speed had minimal effect on sound transmission.