Wikipedia

# Sound exposure

Sound exposure is the integral, over time, of squared sound pressure. The SI unit of sound exposure is the pascal squared second (Pa2·s).

Sound exposure, denoted E, is defined by

${\displaystyle E=\int _{t_{0}}^{t_{1}}p(t)^{2}\,\mathrm {d} t,}$

where

• the exposure is being calculated for the time interval between times t0 and t1;
• p(t) is the sound pressure at time t, usually A-weighted for sound in air.
For other uses, see Sound level.

Sound exposure level (SEL) is a logarithmic measure of the sound exposure of a sound relative to a reference value.
Sound exposure level, denoted LE and measured in dB, is defined by

${\displaystyle L_{E}={\frac {1}{2}}\ln \!\left({\frac {E}{E_{0}}}\right)\!~\mathrm {Np} =\log _{10}\!\left({\frac {E}{E_{0}}}\right)\!~\mathrm {B} =10\log _{10}\!\left({\frac {E}{E_{0}}}\right)\!~\mathrm {dB} ,}$

where

• E is the sound exposure;
• E0 is the reference sound exposure;
• 1 Np = 1 is the neper;
• 1 B =1/2 ln 10 is the bel;
• 1 dB = 1/20 ln 10 is the decibel.

The commonly used reference sound exposure in air is

${\displaystyle E_{0}=400~\mathrm {\mu Pa^{2}\cdot s} .}$

The proper notations for sound exposure level using this reference areLW/(400 μPa2⋅s) orLW (re 400 μPa2⋅s), but the notationsdB SEL,dB(SEL), dBSEL, or dBSEL are very common, even if they are not accepted by the SI.

1. "Letter symbols to be used in electrical technology – Part 3: Logarithmic and related quantities, and their units", IEC 60027-3 Ed. 3.0, International Electrotechnical Commission, 19 July 2002.
2. Ross Roeser, Michael Valente, Audiology: Diagnosis (Thieme 2007), p. 240.
3. Thompson, A. and Taylor, B. N. sec 8.7, "Logarithmic quantities and units: level, neper, bel", Guide for the Use of the International System of Units (SI) 2008 Edition, NIST Special Publication 811, 2nd printing (November 2008), SP811 PDF

Sound exposure Language Watch Edit Sound exposure is the integral over time of squared sound pressure The SI unit of sound exposure is the pascal squared second Pa2 s Sound measurementsCharacteristicSymbols Sound pressure p SPL LPA Particle velocity v SVL Particle displacement d 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 TLvteMathematical definition EditSound exposure denoted E is defined by E t 0 t 1 p t 2 d t displaystyle E int t 0 t 1 p t 2 mathrm d t where the exposure is being calculated for the time interval between times t0 and t1 p t is the sound pressure at time t usually A weighted for sound in air Sound exposure level EditFor other uses see Sound level Sound exposure level SEL is a logarithmic measure of the sound exposure of a sound relative to a reference value Sound exposure level denoted LE and measured in dB is defined by 1 L E 1 2 ln E E 0 N p log 10 E E 0 B 10 log 10 E E 0 d B displaystyle L E frac 1 2 ln left frac E E 0 right mathrm Np log 10 left frac E E 0 right mathrm B 10 log 10 left frac E E 0 right mathrm dB where E is the sound exposure E0 is the reference sound exposure 1 Np 1 is the neper 1 B 1 2 ln 10 is the bel 1 dB 1 20 ln 10 is the decibel The commonly used reference sound exposure in air is 2 E 0 400 m P a 2 s displaystyle E 0 400 mathrm mu Pa 2 cdot s The proper notations for sound exposure level using this reference are LW 400 mPa2 s or LW re 400 mPa2 s but the notations dB SEL dB SEL dBSEL or dBSEL are very common even if they are not accepted by the SI 3 References Edit Letter symbols to be used in electrical technology Part 3 Logarithmic and related quantities and their units IEC 60027 3 Ed 3 0 International Electrotechnical Commission 19 July 2002 Ross Roeser Michael Valente Audiology Diagnosis Thieme 2007 p 240 Thompson A and Taylor B N sec 8 7 Logarithmic quantities and units level neper bel Guide for the Use of the International System of Units SI 2008 Edition NIST Special Publication 811 2nd printing November 2008 SP811 PDF Retrieved from https en wikipedia org w index php title Sound exposure amp oldid 1038436884, wikipedia, wiki, book,

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