An ultrasonic transducer for wind turbine applications. The transducer includes a housing with a central diaphragm portion, a peripheral wall thereabout, and a flexure portion supporting the diaphragm portion relative to the peripheral wall. The apex of a cone is secured to the housing central diaphragm portion and the cone has a peripheral rim secured to the metal housing peripheral wall. A driver such as a piezoelectric element is secured to the housing central diaphragm portion opposite the cone apex.

A light source suitable for use in a conventional light socket of a conventional light fixture includes an integral sonic repelling device operable to generate sound at a frequency that is inaudible to humans but that repels pests such as mice and rats.

A broadband ultrasonic transducer device (UTD) is disclosed that utilizes a plurality of narrow-band piezo electric elements grouped into single-frequency sub-arrays to provide a relatively simple, highly-reliable deterrent unit (DU) capable of emitting ultrasonic energy over a wide coverage area and at a sound pressure level that meets or exceeds other DU approaches. In an embodiment, the broadband UTD includes a housing portion configured to couple to a plurality of piezo sub-array plates. Each piezo sub-array plate includes a plurality of pockets or cavities to receive respective narrow-band (e.g., 1-3 kHz) piezo electro transducer elements with characteristics, e.g., geometries and material composition, that cause each to emit ultrasonic energy at a particular resonant frequency. A controller of the UTD implements a control scheme to emit ultrasonic energy in a plurality of output modes including a white noise node and a single-frequency mode for deterrence applications.