Unit of electrical resistance. Named after its founder Georg Ohm, Ohms law states that current varies in direct ratio to the wires' resistance.

The name for Philips and Sony's recordable CD standard published in 1990. In addition to specifying the first recordable CD formats, the specification also deals with how the data is managed, hybrid disc and multisession operation amongst other things.

An electronic circuit designed to generate a period electrical waveform at a particular frequency. Oscillators are found in computers, wireless receivers and transmitters, and music synthesizers. Early synthesizers used oscillators as the raw source for creating sound, using filters and envelops to shape the sounds.

A condition where the signal levels present exceed the capabilities of a device, causing an undesirable consequence, such as distortion.

Used during analog to digital and digital to analog conversion and refers to the process whereby the converters sample at much higher rates than the base frequency. This allows the filters to be much gentler in slope, which results in less phase distortion in the audible spectrum.

Personal Computer Memory Card International Association was organized in 1989 to promote standards for credit card-size devices that can fit in a portable computer. Originally designed as a storage device, it later expanded to other applications such as modems and networking. For audio and video users, the technology has been extended to include input/output devices.

Psychoacoustically Optimized Wordlength reduction is a sonically transparent digital word length reduction algorithm, reducing 20, 24, and even 32-bits files to the CD standard 16-bit format. Pow-r is technically not noise shaping, although it performs a similar function, and aims to retaining a high degree of perceived dynamic efficiency with very low noise.

Peak Program Meter. A type of meter designed to register signal peaks rather than the average level of an electrical source.

Pulses per Quarter Note refers to the timing resolution of a MIDI sequencer. It refers to the number of subdivisions within a quarter note that a MIDI event could possibly start on.

Pressure Zone Microphone. Also know as a boundary microphone. The microphone consists of electret capsule mounted to a backing plate, which is then placed on any kind of flat surface. Useful for conferences, ambient microphones or for recording piano where isolation from other sources is essential.