In various embodiments, vibro-acoustic transducer arrangements in accordance herewith are optimized for sensing and transducing acoustic phenomena occurring within a patient's body, and manifesting themselves at the skin surface with frequencies ranging from 0.001 Hz to 10 kHz. Strategies for effectively coupling to the skin include judicious mismatching of mechanical impedance, the use of impedance-matching gels or liquids, a shaped (e.g., domed) pickup, material selection, and/or a peripheral leaf-spring arrangement permitting relative movement between inner and peripheral diaphragm portions. The spring stiffness or spring compliance of the leaf springs may be selectively chosen to optimize the frequency response of the sensor.