Integration of duration and frequency cues in discrimination between pure tones
Blas Espinoza-Varas · The Journal of the Acoustical Society of America · 1978
The acoustic cues that underlie discrimination of complex sounds (e.g., speech) are often multidimensional and sequential (i.e., not all the dimensions vary at the same time). In this work we explored whether the information provided by the various dimensions can be integrated to improve discrimination, for the case of cues consisting of a change in duration followed by a change in frequency. The procedure was a same-different discrimination between pairs of tones. Each pair consisted of two 80-ms, 1500-Hz tone bursts separated by a 60-ms interval. For the “different” trials, the comparison pair contained increments in the duration (Δt) of the first tone and/or in the frequency (Δf) of the second tone. For various values of Δt, the value of Δf required to maintain a constant performance level was measured, and vice versa. A tradeoff between the values of Δt and Δf required for d′ = 2.0 was observed, suggesting that the effects of the two dimensions were integrated. The tradeoff was most prominent when the increments in duration and frequency were matched in terms of their discriminability. The results are compared with the prediction that d′Δt+Δf = [dΔt′2 + dΔf′2]1/2. [Work supported by NINCDS.]