National Association of Broadcasters/National Association of Radio and Television Broadcasters: Standards organization.
Tape-recording equalization curve established by the National Association of Broadcasters.
Equivalent to O VU.
A unit of magnetic flux. The flux density, or fluxivity, of a test tape is measured in nanowebers per meter.
In tape recording, the preemphasis and subsequent deemphasis standards used in America and Japan.
The acoustic radiation field close to the speaker or some other acoustic source.
The narrow end of a horn, where it connects to the driver.
A gas diode that emits an orange glow, and operates as an indicator, protective switch, regulator, relaxation oscillator, or divider.
Improvement on the original Piloton system of sync pulse in which two thin tracks are positioned at the centre of the tape (where they are more reliable) recorded in opposite phase (push-pull) and so do not reproduce in a full-track scan.
A comparatively elaborate electrical or electronic circuit arrangement.
Unit of force. The sound pressure level at the threshold of hearing is 0.00002 newtons/m2.
Unwanted signal consisting of a mixture of random electrical signals. Also the sum of all unwanted signals such as hum, hiss, rumble, interference, distortion, etc.
The long term noise within any environment, in the absence of extraneous sound sources.
Literally, roughness noise. An increase in noise level over a narrow bandwidth on either side of a recorded frequency.
The noise level of the surrounding environment.
A filter, such as a notch or cut-off filter, designed to filter out narrow band noise, or noise at either frequency extreme.
An expander, whose threshold is set to attenuate low level signals, such as leakage, rumble, etc.
Noise that is a function of a mechanical contact with, or by, a moving object.
The amplitude of a noise. Usually refers to the decibel level of a steady state noise.
Noise components across the entire audio bandwidth that are produced by any audio signal.
Noise that is confined to, or measured across, a relatively narrow bandwidth.
Wideband noise that maintains constant energy per octave.
The noise of an audio system in a static condition; that is, with no applied signal.
An agreed set of empirical curves relating octave band sound pressure level to the center frequency of the octave bands, each of which is characterized by a "noise rating" (NR), which is numerically equal to the sound pressure level at the inter section with the ordinate at 1,000 Hz. The "noise rating" of a given noise is found by plotting the octave band spectrum on the same diagram and selecting the highest noise rating curve to which the spectrum is tangent.
Process using gain control devices to improve the signal to noise ratio. (See Burwen, DBX and Dolby.)
The noise level of a tape, after it has been erased.
A noise measured on a voltage scale.
A wideband noise that contains equal energy at each frequency.
Noise that is distributed over most, or all, of the audio bandwidth. See Pink, White Noise.
That part of the distortion arising in a non-linear system (i.e. a system whose transmission properties are dependent on the instantaneous magnitude of the excitation) which is due to the non-linearity of the system.
Sockets on a jack field having permanently wired interconnections.
Bandpass filter tuned to a very narrow frequency band