ŁĘTOWSKI, T., and J. M. CARAVELLA. “Sound Levels Produced at and in the Occluded Ear of the Talker”. Archives of Acoustics 19, no. 2 (June 30, 1994): 139–146. Accessed April 18, 2026. http://acoustics.ippt.gov.pl/index.php/aa/article/view/1068.