Destriza, W.-N.C., De Castro, R.B. and Enriquez, H.M. 2015. An Experimental Study on Maximum Sound Output Capabilities and Preferred Listening Levels Using Different Earphone Types. Philippine Journal of Otolaryngology Head and Neck Surgery. 30, 1 (Jun. 2015), 6–13. DOI:https://doi.org/10.32412/pjohns.v30i1.371.