1.1 This laboratory test method measures the degree to which reflected sound is attenuated by the most commonly found vertical surfaces in open-plan spaces. Reflection of sound from vertical surfaces is a concern in open-plan spaces because it can reduce speech privacy. The vertical surfaces covered by this test method include wall finishes such as sound-absorbent panels, and furniture panels or screens. It does not cover such items as window finishes or furniture other than panels.

1.2 This test procedure was originally developed using the foot-pound system of units for prescribing measurement positions and distances. However, the use of SI units is preferred by ASTM. For this reason, dimensions are provided in SI units, with approximate foot-pound conversions indicated in parentheses.

1.2.1 Unless otherwise qualified, all dimensions specified in this test method shall be understood to have a tolerance of ± 25 mm (± 1 in.), even though the indicated approximate conversion of the numerical dimensions given will not always be accurate to this extent. All measurements shall be made in SI units or the corresponding exact foot-pound units.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.