Sound power level or acoustic power level is a logarithmic measure of the sound power in comparison to a specified reference level. // Sound pressure Sound pressure is the pressure deviation from the local ambient pressure caused by a sound wave. ... It has been suggested that this article or section be merged into Sound pressure. ... Particle velocity is the velocity v of a particle (real or imagined) in a medium as it transmits a wave. ... The particle velocity level or the sound velocity level tells the ratio of a sound incidence in comparison to a reference level of 0 dB. It shows the ratio of the particle velocity v1 and the particle velocity v0. ... Particle displacement or particle amplitude (represented in mathematics by the lower-case Greek letter ξ) is a measurement of distance (in metres) of the movement of a particle in a medium as it transmits a wave. ... The sound intensity, I, (acoustic intensity) is defined as the sound power Pac per unit area A. The usual context is the measurement of sound intensity in the air at a listeners location. ... 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). ... Sound power or acoustic power Pac is a measure of sonic energy E per time t unit. ... The sound energy density or sound density (symbol E or w) is an adequate measure to describe the sound field at a given point as a sound energy value. ... The sound energy flux is the average rate of flow of sound energy for one period through any specified area. ... The acoustic impedance Z (or sound impedance) is the ratio of sound pressure p to particle velocity v in a medium or acoustic component. ... The speed of sound c (from Latin celeritas, velocity) varies depending on the medium through which the sound waves pass. ... A logarithmic scale is a scale of measurement that uses the logarithm of a physical quantity instead of the quantity itself. ... Sound power or acoustic power Pac is a measure of sonic energy E per time t unit. ...

The measure of a ratio of two sound powers is Sound power or acoustic power Pac is a measure of sonic energy E per time t unit. ...

where W₁ and W₀ are the powers.

The sound power level is given the symbol L_w or SWL and is measured in "dBW", which stands for decibel with the suffix for watts. Decibels are dimensionless. SPL stands for sound pressure level, and is not the same thing. dBW is an abbreviation for the strength of a signal expressed in decibels relative to one Watt. ... The decibel (dB) is a measure of the ratio between two quantities, and is used in a wide variety of measurements in acoustics, physics and electronics. ... The watt (symbol: W) is the SI derived unit of power. ... In the physical sciences, a dimensionless number (or more precisely, a number with the dimensions of 1) is a quantity which describes a certain physical system and which is a pure number without any physical units; it does not change if one alters ones system of units of measurement... It has been suggested that this article or section be merged into Sound pressure. ...

If W₀ is the standard reference sound power, where

(W = watt), then instead of "dB", dB SWL is used. (SWL = sound power level).

Table: Sound power and und sound power level of some sound sources

Usable music sound (trumpet) and noise sound (excavator) have both the same sound power of 0.3 watts, but will be judged psychoacoustically to be different levels. It has been suggested that this article or section be merged into refrigeration. ... Mechanical desktop typewriters, such as this Underwood Five, were long time standards of government agencies, newsrooms, and sales offices. ... The Bell 206 of Canadian Helicopters Robinson Helicopter Company (USA) R44, a four seat development of the R22 A helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors. ... Alternative meaning: Chainsaw (computer program) A chainsaw (also spelled chain saw) is a portable mechanical, motorized saw. ... A tracked excavator by Daewoo. ... Trumpeter redirects to here. ... A portable jackhammer being used to break up a roadsurface in roadworks. ... A machine gun is a fully-automatic firearm that is capable of firing bullets in rapid succession. ... The term, rock concert, refers to a musical performance in the style of any one of many genres inspired by rock and roll music. ... A Greek amphora depicting Odysseus encounter with the sirens. ... Turbojets are the simplest and oldest kind of general purpose jet engine. ... A cold (un-ignited) rocket engine test at NASA A rocket engine is a heat engine that can be used for spacecraft propulsion as well as terrestrial uses, such as missiles. ... Psychoacoustics is the study of subjective human perception of sounds. ...

External links

• Ohm's law of the acoustics - calculator
• Formulas - Connection of acoustic sizes for even progressive acoustic waves -pdf