Sound at frequencies above the audible range, namely above 20 kHz, audible only to various non-human species. Because of its very short WAVELENGTH in the megahertz range, ultrasound is used as a safe alternative to X-ray photography in medical diagnosis. Ultrasound scanning is sometimes called sonography.
The device, successor to the MAGNETIC WIRE recorder, which since the 1940s (when it was called the sound mirror) has been the most commonly used means of storing and reproducing an AUDIO signal.
Although often employed interchangeably with ACOUSTICS, the term might better be restricted to the technology dealing with the practical applications of SOUND, as distinct from the pure science of acoustics. (It will be noted, however, that the contemporary acoustical engineer or acoustician is often mostly involved with the practical applications of sound.)
(Greek: monos = one; phone = sound) A form of reproduction which records, transmits and reproduces the original sound along a single CHANNEL, regardless of the number of loudspeakers used. All components of the sound are combined or MIXed into one SIGNAL, including AMBIENCE and REVERBERATION, and therefore only the sense of depth may be simulated or reproduced.