Horn (acoustic)

Acoustic horns are found in nature in the form of the burrows constructed by male mole crickets to amplify their song.

Typically, these use any fundamental frequency from around 120–250 Hz, are about 120 dB SPL, and are powered by compressed air.

These are generally not exponential in configuration, and are used to modify the standing wave patterns of the instrument, and thereby the musical notes which can be produced.

Acoustic horns are found in nature in the form of the burrows constructed by male mole crickets to amplify their song.

Its song is loud enough to make the ground vibrate; its 3.5 milliwatts of mechanical power delivers a peak of 92 decibels at a distance of one metre.

A traditional reed bulb horn
A patent horn loudspeaker
Male mole cricket in singing position in burrow. The burrow is shaped as a double exponential horn with bulb.