Pulse Song (audio) Princeton University Loading audio... Caption When fruit flies court, the male chases the female as he vibrates his wings to produce roughly five-second serenades, or "bouts." The song is composed of a buzzing sound known as a "sine" and a purring sound called a "pulse." This audio file is of a pulse. The male switches off between the pulse and sine every several milliseconds, so that the two sounds seem almost simultaneous. Credit Audio file courtesy of Philip Coen, Princeton Neuroscience Institute Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.