Old Session Stills : 2007-2011 : 3424 Commercial St.
Latest Forum Posts
A TONE having more than a single FREQUENCY component. For instance, a tone consisting of a FUNDAMENTAL and OVERTONEs or HARMONICs, may be said to be complex.
The subjective impression of FREQUENCY, in the same sense that LOUDNESS is the subjective sense of the INTENSITY or AMPLITUDE of a sound. As such, pitch is a psychoacoustic variable, and the degree of sensitivity shown to it varies widely with people. Some individuals have a sense of remembered pitch, that is, a pitch once heard can be remembered and compared to others for some length of time; others have a sense of absolute pitch called PERFECT PITCH.
If two TONEs are about 15 Hertz or less apart, INTERFERENCE will result from their similar though not exactly identical frequencies. Gradually they will move out of PHASE until at 180° destructive interference results, producing diminished loudness. When they move back into phase, constructive interference will produce increased loudness. Thus, beats are a form of AMPLITUDE MODULATION. As two frequencies are brought closer together, the beats will gradually slow down and disappear when they become identical.
When a system with a natural vibrating FREQUENCY is stimulated by an outside force of the same frequency, the system can be set in a motion called VIBRATION. As the frequency of the stimulus closely approaches that of the system, OSCILLATION occurs, which reaches a maximum AMPLITUDE at the natural resonant frequency.