CI-81-12-1 -- The Relation between Sound Power Level and Sound Pressure Level Outside of Laboratories PDF

This paper is divided into two parts, (1) Part 1, the Problem. This part was originally published in Noise Control Engineering, Volume 14, No.1, Jan.- Feb. 1980, under the same title. It is reproduced here with their permission. And in Part 2, Proposed Noise Ratings for Various Kinds of Equipment, a review of the various methods of test and rating for equipment noise that have been proposed by various interested groups. The conclusions reached in the main text should be kept in mind in assessing the utility of the different proposals: for labeling regulations, any relation between sound pressure level and sound power level should be based upon the "sound source out in space" model, rather than the "source against reflector" model.

There is a current concern in the Environmental Protection Agency (EPA) and in the Technical Committees of the International Organization for Standardization (ISO) and the American National Standards Institute (ANSI) as to whether the noise output of household appliances and other similar equipment should be expressed in terms of the sound power level of the device or the sound pressure level which it produces at the user's ears, or both.