Vibro-acoustic response of tympanic-membrane-like models

Equivalent measurements to the Real Ear Measurement (REM) procedure are sought using faster and contactless Laser Doppler Vibrometry. A feasibility study has been performed on tympanic-membrane-like rubber and latex models, in which the vibro-acoustic response was measured using both standard REM equipment and a PSV-500-HM Laser Doppler Vibrometer (LDV). The membrane surface velocity distribution was measured by the LDV and the transfer function between the forcing acoustic field and the vibration response of the membrane was calculated. The variability in the transfer function due to membrane shape, membrane type, and measurement position was determined. This study indicates that the transfer functions from measurements in the neighbourhood of the modelled umbo spot repeated several days apart were found to be consistent within typical clinical measurement tolerances. These results seem to indicate that Laser Doppler Vibrometry has the potential for replacing the standard REM procedure and equipment in patient-specific tests.