Abstract
The effects of leading and trailing tones (interference tones) on frequency discrimination of a brief tone are investigated. Changes in frequency discrimination are measured as a function of frequency difference between the interference and signal tone, and interval between the two tones (Δt). The results obtained are as follows : (1) The frequency discrimination for a tone with the leading tone is almost unchanged, even if Δt is increased. On the other hand, frequency DL for a tone with the trailing tone increases gradually as Δt decreases. (2) In the case where the frequency of the interference tone is changed as a parameter, frequency DL takes its minimum value when the interference tone and the test tone has the same frequency. Frequency discrimination becomes worse, however, in the presence of interference tones with the frequency slightly different from the test tone. The effect of the interference tone is maximum for the frequency difference of 50 Hz. In theses experiments it is found that the interference effect of trailing tone on frequency discrimination is greater than that of the leading tone. Finally a model of the mechanism for frequency analysis in hearing was proposed and it can explain the results fairly well.
