Hearing aids : electrical principles of modern hearing aids and problems in design, together with a discussion of audiometry and other considerations pertaining to fitting instruments to the varying needs of the hard of hearing
by Fred W. Kranz
Bok Engelsk 1939
| Utgitt | Emsford, N.Y. : Sonotone Corp. , 1939
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|---|---|
| Omfang | 39 s. : ill.
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| Emner |
