The Tone Decay Test

Abstract

The purpose of this investigation was to estimate: (1) The correlation between tone decay degree and topographical diagnosis, age and pure tone threshold. (2) The significance of applying different test frequencies. A total of 2123 ears were tested in 500, 2000 and 4000 Hz by means of a manual method. A strict correlation was found, on the one side, between a high degree of tone decay and cerebello-pontine angle tumours and on the other side a low degree or missing tone decay in normal hearing ears. In six diagnostic groups the per stimulatory threshold shift was unequally distributed among the different test frequencies. The age factor does not influence the tone decay noticeably, while the degree of hearing loss in some cases seems to be an important factor. Two test frequencies are recommended, 500 and 2000 Hz.