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 study of the relationship between physical SOUNDs and the brain's interpretation of them. Until recently, psychoacoustics has devoted more attention to the behaviour of the peripheral auditory system than to the details of cognitive processing.
In music, an adjective referring to HARMONY and its principles. In ACOUSTICS, when a vibrating object, such as a string, is set in motion, it vibrates both as a whole, with a FREQUENCY called the FUNDAMENTAL, and, with lesser intensity, in sections as well. If these smaller lengths are integer fractions (1/2, 1/3, 1/4, ...) of the total length of the string, their frequencies of OSCILLATION are called harmonics, and are integer multiples of the fundamental.
(Greek: stereos = solid; phone = sound) Generally, a term used to refer to the spatial distribution of sound, normally using AUDIO technology. More specifically, a form of reproduction which records, transmits and reproduces the original sound with two CHANNELs, regardless of the number of loudspeakers used. Also abbreviated to stereo.