Acoustic Glossary


J : Sound and Vibration Terms, Definitions, Units, Measurements ...

Jerk a vector quantity that specifies time rate of change of acceleration - units m/s3

Joule (J) the derived SI unit of work or energy.


A Joule is the work done by a force of 1 newton acting through a distance of one metre.

Joule = N·m = Kg·m2/s2 = W·s = Pa·m3 = 107 ergs = C·V
where kg is the kilogram, m is the metre, s is the second, N is the newton, Pa is the pascal, W is the watt, C is the coulomb, and V is the volt.

See also sound energy.

Joule per cubic metre (J/m3) • see sound energy density

Joule per kilogram (J/kg) • see specific energy

Joule per second (J/s) • see sound power

Joule second per metre squared (J·s/m2) • see sound energy fluxsound power density

Judged Perceived Noise Level Definition IEC 801-29-10, sound pressure level, in decibels, of a frontally presented octave band of pink noise centred on 1 kHz and lasting for two seconds, that is subjectively judged equally noisy as a given sound.

See also • perceived noise level

HomeGlossary SearchCertified Instrumentation for Hire