Acoustic function before and after operation for otosclerosis.

AN INVESTIGATION of the acoustic function is essential in the diagnosing of otosclerosis. In the present paper an account is given of tests made with tuning forks, monochord, whispered voice and speech as well as with the audiometer and possibly Fowler's test. None of these functional tests are ideal, and discrepancies are often experienced between the various tests. Tuning forks and the monochord are not quite satisfactory when patients with impaired hearing are concerned. Trowbridge,1 who has for several years been doing routine hearing tests in the United States Army, using both tuning forks, speech and audiometer, stated that tuning forks can be usefully applied only with intelligent persons, but "the results were often confusing and contradictory, and precise conclusions could not be made from them alone." The monochord is of importance for the fixing of the upper tone limit. Hall 2 holds that the assessment of the upper tone