Exploring variations to ASTM E336 directional sound source positioning

This paper explores variations to the procedures presented in ASTM E336 Standard Test Method for Measurement of Airborne Sound Attenuation between Rooms in Buildings. Per the Test Standard, directional sound sources must be aimed into corners away from the test partition. For source rooms horizontally adjacent to occupied spaces on all sides, multiple loudspeaker positions are needed to measure noise isolation in all directions. Measurements made in 4 office spaces are presented, each made in two ways: firstly in compliance with the Standard; and secondly, with sound sources orientated and operated differently, to explore whether using a single configuration of directional loudspeakers can produce similar results. Variations in the results are discussed, and suggestions are provided for future work.