High Frequency Sound Devices Lack Efficacy in Repelling Birds

Ultrasonic or high-frequency sound-producing devices are marketed as a scaring or frightening method for bird control. Although inaudible to humans, most birds also do not hear in the ultrasonic frequency ranges of above 20,000 Hz, thus the credibility of advertised claims raises questions. A review of efficacy studies conducted and published by a number of researchers fails to demonstrate the usefulness of such bird control devices.