A systematic investigation to assess the merits of measurement preconditions critical to speech privacy standards

As with any field of science, the limits of theory are regularly tested to make way for more reliable testing standards. However, without a defined understanding of scope and purpose, the line between theory and practice—that which is already obscure—becomes increasingly difficult to identify. In the following investigation, the author reviews the scope and purpose of certain acoustical standards (ASTM E90, E336, E1130, E1573, E2638, and ANSI/ASA S12.2, S12.72) to clarify the context for which meaningful guidance is needed. More specifically, topics of interest include (1) effects of measurement locations and positions, (2) effects of measurement procedure, (3) effects of measurement instrumentation, (4) differences between operators, and (5) effects of architectural features on sound (i.e., spatial, spectral and temporal properties). To offer resolute understanding of the impact of each recommendation, the measurement methods within this investigation exceed those provided by the Standards. This provision is intended to afford meaningful insight as to the theoretical and practical limitations of the measurement of sound in the built environment—in contrast to the more limited data that would be available if testing is in accordance with the relevant Standards. The variability due to each guideline is quantified and reported.