Practical unit of electrical power equal to one joule per second. (In a DC circuit the number of watts is equal to the product of the volts and amperes; in an AC circuit it is equal to the product of the volts and amperes multiplied by the power factor.)
The shape of the graph representing the successive values of a varying quantity.
Of a sinusoidal plane progressive wave. The perpendicular distance between two wavefronts in which the phases differ by one complete period. The wavelength is equal to the wave velocity divided by the frequency.
Unit of magnetic flux.
The noise measured within the audio frequency band using an instrument which has a frequency selective characteristic.
Filtering a frequency response, prior to measurement.
A filtering network, corresponding to the ear's sensitivity at 40 phons.
A filtering network, corresponding to the ear's sensitivity at 70 phons.
A filtering network, corresponding to the ear's sensitivity at 100 phons.
A filter used for weighting a frequency response, prior to measurement.
Subjective description of a sound with a high proportion of reverberation present.
Random noise signal having an equal amount of energy per hertz. Therefore the energy between 100 and 200 Hz is equal to that between 10,000 and 10,200 Hz.
An acoustically transparent filter, placed over a microphone to shield it from wind-induced vibration.
A low frequency loudspeaker.
Repetitive slow variations in tape speed.
Deviation of frequency resulting from irregular motion in the recording, from duplication or reproduction of a tone, or from deformation of the recording medium.
The length of the tape's path along which tape and head are in intimate contact. Sometimes measured as the angle of arrival and departure of the tape with respect to the head.