Hearing aids.
Contributors: United States. National Bureau of Standards.
Series: Circular of the National Bureau of Standards -- 534
Publisher: U.S. Govt. Print. Off.
Published: 1953
Place of publication: Washington
Language: eng
Number of pages: 18
Subjects: Hearing aids
Notes: Issued as revision of the Bureau's Circular 516 with title: Selection of hearing aids.

"Issued March 2, 1953."

At head of title: United States Department of Commerce. National Bureau of Standards.