The use of reflected SOUND WAVEs for obtaining environmental information. Certain animals, such as the bat and the porpoise, emit pulses of extremely high frequency sound (up to 50 kHz for bats, and up to 170 kHz for porpoises and whales) in narrow, intense streams. The REFLECTION, or ECHO, of these sounds supplies information regarding the nature and location of objects in the environment. When an emission of varying frequency is used, such as with bats, the echoes, travelling varying distances to the ear, are heard as different frequencies in each ear, thus supplying directional information.
The control of sound levels to ensure suitable placement between the lowest and highest distortion-free levels of an electroacoustical system.
An adjective describing any process involving the transfer of a SIGNAL from acoustic to electrical form, or vice versa. Most commonly, TRANSDUCERs such as the MICROPHONE or LOUDSPEAKER are examples of this process.
Timbre or tone QUALITY is determined by the behaviour in time of the FREQUENCY content or SPECTRUM of a sound, including its TRANSIENTs which are extremely important for the identification of timbre.