ASTM E 2638 : 2024

1.1This test method describes a test procedure for measuring the degree of speech privacy provided by a closed room, for conversations occurring within the room, and with potential eavesdroppers located outside the room.

1.2The degree of speech privacy measured by this method is that due to the sound insulation of the room structure—including the walls, floor, ceiling and any other elements of the room boundaries—and to the background noise at listening positions (receiving points) outside the closed room.

1.3Potential eavesdroppers are assumed to be unaided by electronic or electroacoustic equipment, and not touching the room boundaries. Determined efforts to eavesdrop are not addressed.

1.4The method may be applied to any enclosed room, whether specifically intended to be protected against eavesdropping or not.

1.5The method does not recommend criteria for adequate speech privacy. A non-mandatory Appendix X2 provides guidance on how the results of this test method may be used to estimate the probability of an eavesdropper being able to understand speech outside a closed room, and how to establish criteria for such rooms.

1.6The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.7This 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.8This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.