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.
When sounds are conducted separately and independently to each ear via tubes or headphones, the sounds are said to be heard dichotically. In various psychoacoustic experiments, isolation of the function of each ear is desirable, such as in the testing or simulation of BINAURAL HEARING with the PRECEDENCE EFFECT, or in testing preferences for different sounds presented simultaneously to separate ears.
Any VIBRATION in the air or other medium, some types of which are able to cause a sensation of hearing.
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.