99/561983 DC : APR 99

1 Scope
2 Normative references
3 Terms and definitions
4 Sound distribution in a room
    4.1 General
    4.2 Spatial sound distribution curves
          4.2.1 Reference spatial sound distribution
                  curves
          4.2.2 Spatial sound distribution curves in
                  frequency bands and for a given
                  frequency spectrum
          4.2.3 Frequency-normalized spatial sound
                  distribution curve C
5 Measurement of the spatial sound distribution curve
    5.1 Specifications regarding the sound source used
          for the test
          5.1.1 Performance requirements to be met by the
                  source
          5.1.2 Calibration and verification of the sound
                  output of the source
          5.1.3 Location of the source
          5.1.4 Sound output versus background noise
          5.1.5 Verification of a spatial sound
                  distribution curve
    5.2 Measurement instrumentation
    5.3 Measurement path and points
          5.3.1 Measurement path
          5.3.2 Measurement points
    5.4 Measurement procedure
    5.5 Representation of the measured data
    5.6 Factors influencing the measurement results
6 Modelling of the measured spatial sound distribution
    curve in view of the evaluation of the acoustical
    performance of workrooms
    6.1 Distance ranges
    6.2 Determination of the rate of spatial decay of
          sound pressure levels per distance doubling.DL2
    6.3 Determination of the excess of sound pressure level
          with respect to a reference sound distribution
          curve, DLf
          6.3.1 Value of the excess of sound pressure
                  level over a distance range [rn,rm]
                  and in a given octave band
          6.3.2 Value of DLf'r of DLf at a specified
                  distance r and for a given octave band
    6.4 Evaluation of the measured data
7 Information to be recorded and reported
Annex A (normative) Performance requirements for the
sound source to be used for the test
Annex B (informative) Example of use of this International
Standard
Bibliography

Defines a procedure for measurement of the spatial sound distributiojn curve(s) of a specified workroom. Gives a procedure for determination from measured data, two descriptors of the acoustical performance of a workroom, that is the excess of sound pressure level regarding a free field and the sound pressure level decay per distance doubling.