A parabolic microphone is a microphone that uses a parabolic reflector to collect and focus sound Wavesonto a receiver, in much the same way that a parabolic antenna (e.g., satellite dish) does with radio waves.

Several approaches have been developed for effectively using a microphone in less-than-ideal acoustic spaces, which often suffer from excessive reflections from one or more of the surfaces (boundaries) that make up the space.

"Figure 8" or bi-directional microphones receive sound from both the front and back of the element. Most ribbon microphones are of this pattern.

The most common unidirectional microphone is a cardioid microphone, so named because the sensitivity pattern is heart-shaped. A hyper-cardioid microphone is similar but with a tighter area of front sensitivity and a smaller lobe of rear sensitivity. A super-cardioid microphone is similar to a hyper-cardioid, except there is more front pickup and less rear pickup.

A unidirectional microphone is sensitive to sounds from only one direction. The sound intensity for a particular frequency is plotted for angles radially from 0 to 360°.

Describes a device such as a microphone or antenna that operates equally well in all directions.

An audible change in the level of background noise with varying audio levels. Most often used to describe an undesirable characteristic of companding systems. A faster, somewhat more noticeable form is called pumping.

To reduce the amount of energy contained in an electrical or radio frequency signal. Also, to reduce the intensity or level of sound waves.

Phase Cancellation

Acoustic overtones that represent the upper and lower octaves of a note. When a note is played, the harmonics ring out along with it, and this, combined with other overtones, gives an acoustic instrument its particular sound. (See Overtones.)