A specific form of polar response of a unidirectional microphone or loudspeaker. It is an inverted heart-shape which has very low sensitivity at the back (180 degrees), but only slightly reduced sensitivity (typically between 3 and 6dB) at the sides (90/270 degrees).

(Also known as a Carbon Button Microphone). An obsolete form of microphone in which carbon granules are contained between two metal contact plates, one of which acts as the diaphragm and moves in response to sound waves. The microphone has to be biased with a DC voltage which causes a current to pass from one metal contact plate, through the carbon granules, to the other metal contact plate. The varying pressure exerted on the carbon granules by the moving diaphgram causes a varying resistance and thus a varying current which is analogous to the sound waves. Carbon Button Microphones were used in the very early days of sound recording and broadcasting, as well as in domestic telephones up until the 1980s when electret capsules became more commonplace.

An alternative term for a transducer which converts acoustic sound waves into an electrical signal.

A collection of digital data comprising eight bits.

(Also sometimes referred to as a buss) An electrical signal path along which multiple signals may travel. A typical audio mixer contains several (mix) buses which carry the stereo mix, subgroups, the PFL signal, the aux sends, and so on. Power supplies are also fed along buses.

A term most commonly used in reference to a software fault or equipment design problem. In the context of sound recording a bug may also refer to a contact microphone.

A buffer is essentially a short term data storage facility used to accommodate variable data read or write periods, temporarily storing data in sequence until it can be processed by, or transferred to, some other part of the system. 

A device that converts breath pressure into MIDI controller data, allowing woodwind players to control synthesizers.

Beats Per Minute.

A specialised microphone where the diaphragm is placed very close to a boundary (eg. wall, floor or ceiling). In this position the direct and reflected sound adds constructively, giving a 6dB increase in sensitivity. It also avoids the comb-filtering that can occur when a conventionally placed microphone captures the direct sound along with strong first reflections from nearby boundaries. Also known as PZM or Pressure Zone Microphone.