ECMA/TR 27 : 2ED 95

1 Scope
2 References
3 Acoustical terminology
  3.1 General
  3.2 The nature of sound
  3.3 The decibels scale
4 Glossary
  4.1 Sound pressure, p, in pascals
  4.2 Sound pressure level, L[p], in decibels
       4.2.1 Single machine
       4.2.2 Adding sound pressure levels
  4.3 Equivalent continuous sound pressure level, L[peq],
       in decibels
  4.4 A-weighted sound pressure level, L[pA], in decibels
  4.5 C-weighted peak sound pressure level, L[pCpeak]
  4.6 Sound power, W in watts
  4.7 Sound power level, L[W],in decibels
  4.8 A-weighted sound power level, L[WA], in decibels
  4.9 Noise emission
  4.10 Emission sound power level and sound pressure level
  4.11 Declared noise emission values
       4.11.1 Declared sound power level, L[WAd], in bels
       4.11.2 Declared sound pressure level, L [pAM], in
              decibels
  4.12 Noise immission
  4.13 Rating sound level, L[r], in decibels
5 Noise emission
  5.1 General
  5.2 Measurement of noise emission
  5.3 Use of noise emission values
6 Noise immission
  6.1 General
  6.2 Determination of noise immission
  6.3 Use of noise immission values
7 Installation noise
  7.1 General
  7.2 Measurement of the installation noise level
  7.3 Prediction of the installation noise level
       7.3.1 Overview and assumptions of the method
       7.3.2 Guidance through the method
       7.3.3 Room categories
       7.3.4 Prediction methods
       7.3.5 Adjustments for screens
       7.3.6 Multiple equipment in a room
       7.3.7 Adjustments for background noise
       7.3.8 Calculations for several locations of
              interest
  7.4 Actual installation noise level
  7.5 Rating level
Annex A - Corrections for the determination of the
          installation noise level
Annex B - Absorption coefficients of some typical
          building materials
Annex C - Supplementary information on the prediction
          theory
Annex D - Bibliography
Annex E - Computer programs for installation noise
          prediction

Defines a method for the prediction of installation noise levels which takes into account the acoustical properties of the room in which computer and business equipment is installed, the location(s) of the noise emitting equipment and their noise emission level(s).