The FREQUENCY content of a sound or audio SIGNAL, often displayed as a graphic representation of amplitude against frequency. The spectrum of a sound is a primary determinant of its perceived TIMBRE.
An ordering of a system of PITCHes, usually in ascending FREQUENCY order. The distance between any two pitches or NOTEs is called an interval.
(German: artificial head). A STEREOPHONIC recording system developed in Germany which employs an artificial head sitting on a resonator similar to a chest cavity. The recording MICROPHONEs are situated within the head, inside an anatomically correct ear canal, at the point where the human eardrum is located. Artificial PINNAE are carefully designed for accurate reflection of the incoming sound in order to achieve the good front-back and height-depth perspective for which the technique is noted.
The atmosphere exerts pressure on all objects in it. When a vibrating body moves in air, it creates slight disturbances of the AMBIENT atmospheric pressure. The AMPLITUDE of these pressure variations is called the sound pressure variation, whereas the effective pressure variation is 0.707 the maximum value. The oscillating variations in sound pressure (called the WAVEFORM of the sound) PROPAGATE in the form of a SOUND WAVE.