@conference{morrow1970acoustic, title = {Acoustic Impedance Calibrator for Mask and Microphone Measurements}, author = {Morrow, Charles T. and Brouns, Austin J.}, booktitle = {Audio Engineering Society Convention 38}, month = {May}, year = {1970}, url = {https://www.aes.org/e-lib/browse.cfm?elib=1302} }