A rare-earth metal element that can be made into magnets, amongst other things. However, it is its properties for making stronger magnets than other materials of the same size that make the element of interest to the audio community.

The Nickel Cadmium is a type of rechargeable battery that is used in electronic equipment. Although they have an even power discharge, they provide less operating time than corresponding alkaline batteries.

The amount of self-noise generated by a piece of electrical equipment when it is at rest (no signal passing through.) All such devices generate noise to some extent or another, and engineers are constantly striving to lower this artifact. Measured in decibels.

A range of technique developed for reducing the amount of noise in an audio signal. Dolby NR is an example of a system designed to reduce the amount of tape noise that is inherent in the analog tape medium.

A system developed to compensate for the quantization errors that are introduced into digital audio files when reducing the bit rate of the data, such as when preparing audio for CD duplication. A certain amount of noise is added to the audio data, which helps to smooth the errors. In which part of the audio spectrum this noise resides varies from one developer to another.

A squelch detection technique that monitors noise at the FM demodulator output, at frequencies above the audio range. A high level of noise in this region indicates a weak or unusable RF signal, or some form of interference.
(See Squelch)

A standard single-channel RF receiver.

A principle used by engineers when designing equipment for the digitization of analog signals. Due to the complex nature of sampling audio, the theory states that for any given sample rate, the maximum bandwidth of the analog source must fall below one half the sampling frequency. If this formula is not followed, errors in the form of aliasing will be introduced into the data file.

Term used to describe the position of a sound source in reference to the microphone recording the source. Generally, a microphone will record best when the source is directly in front of it, but since moving the microphone off-axis results in coloration of the signal, engineers sometimes use it to good effect.

Although used to describe the temporary condition of not being connected to a network, for audio and video purposes the term refers to the processing of files that is not done in real time. Often it is because the computational device is not fast enough to perform the operation while the source is playing. In postproduction, the act of non-linear editing is also considered off-line.