The frequencies crickets love and fear - crickets fear frequencies above 16 KHz and hear only broad ranges of sound - Biology - Brief Article

Science News, Nov 2, 1996

Field crickets (Teleogryllus oceanicus) typically call at a frequency of 4 to 5 kilohertz (kHz), while their archenemies, bats, produce ultrasound ranging from 25 to 80 kHz. Sounds above 16 kHz alarm crickets, giving them a wide margin of safety, Robert A. Wyttenbach of Cornell University and his colleagues report in the Sept. 13 Science.

To determine how crickets respond to sound, they exposed the animals to 20 kHz sounds, which normally cause the insects to flee. However, they repeated the sound so often that the insects' fear disappeared.

Other studies have shown that only a novel sound will reinstate a cricket's normal response. The team tested the animals with a variety of frequencies and found that sounds below 16 kHz did the trick. Sounds above 16 kHz were too similar to 20 kHz for the crickets to discriminate.

This suggests that crickets, like other animals, hear only broad categories of frequencies, although sound, like color, varies continuously.