Date: October 1970
Creator: Corliss, Edith L. R.
Description: From Abstract: "This publication contains information, useful to the hard of hearing, on several topics relating to hearing and hearing aids. This publication represents an extensive revision of NBS Circular 534, Hearing Aids. It includes new material based upon research conducted at the National Bureau of Standards during the intervening years."
Contributing Partner: UNT Libraries Government Documents Department