Shouting (from nyderl. Roeper from roepen - shout ) - tube in the form of a truncated cone, designed for the directional transmission of sound [1] , such as voice or horn signal. The horns were used not only for transmission, but also for directional sound reception - as a means of sound observation in the zenith parts or as devices for improving hearing.
The mouthpiece was invented in 1670 by the Englishman Samuel Morland . He made his first mouthpiece out of glass, and then began to make them out of copper.
A horn having a narrow radiation pattern should have a large outlet and a small angle at the apex of the cone. The horns are ineffective at low frequencies, when the length of the transmitted sound wave is greater than the length of the truncated conical part. Horn boxes, whose radius increases exponentially with distance from the inlet, transmit a signal with less distortion compared to conical horns.
On ships, horns up to 2 meters long were used, with an inlet opening with a diameter of 5 centimeters and an outlet opening of 15-25 centimeters. A horn with a length of 1.5 meters allows you to clearly transmit speech to a distance of 1.5-2 kilometers. Words spoken in a loud voice into a horn 5.5–7.5 meters long can be heard at a distance of up to 5.5 km.
See also
- Megaphone
- Corner reflector
Notes
- ↑ Stanyukovich KM The dictionary of marine terms found in the stories .
Literature
- Krendall I. B. Acoustics. L .: VETA, 1934.
- Morz F. Fluctuations and sound. M.-L., HITTL, 1948.