Gover, Bradford, and John Bradley. “Measurement of Speech Privacy of Closed Rooms Using ASTM E2638 and Setting Criteria in Terms of Speech Privacy Class”. Canadian Acoustics 38, no. 3 (September 1, 2010): 152–153. Accessed November 27, 2024. https://jcaa.caa-aca.ca/index.php/jcaa/article/view/2290.