Sound intensity level

Sound measurements
Characteristic	Symbols
Sound pressure	p, SPL, LPA
Particle velocity	v, SVL
Particle displacement	δ
Sound intensity	I, SIL
Sound power	P, SWL, LWA
Sound energy	W
Sound energy density	w
Sound exposure	E, SEL
Acoustic impedance	Z
Audio frequency	AF
Transmission loss	TL

Sound intensity level or acoustic intensity level is a logarithmic measure of the sound intensity in comparison to the reference level of 0 dB (decibels).

The measure of a ratio of two sound intensities is

$L_{\mathrm {J} }=10\,\log _{10}\left({\frac {J_{1}}{J_{0}}}\right)\ \mathrm {dB}$

where J₁ and J₀ are the intensities.

The sound intensity level is given the letter "L_J" and is measured in "dB". dB is dimensionless.

If J₀ is the standard reference sound intensity, where

$J_{0}=10^{-12}{\frac {W}{m^{2}}}$

(W = watt), then instead of "dB" we use "dB SIL". (SIL = sound intensity level).

External links

• Conversion: Sound intensity level to sound intensity