Effects of signal intensity and noise on the pitch mixture of dichotic chords
Robert Efron, David C. Tanis, E. William Yund · The Journal of the Acoustical Society of America · 1977
The relative salience of the two pitch components (the pitch mixture) of a two-tone dichotic chord (one tone to each ear via earphones) has been shown to be invariant with respect to the interaural intensity difference (ΔI) over a wide range of ΔI [Efron and Yund, J. Acoust. Soc. Am. 59, 889–898 (1976)]. This range of invariance of the pitch mixture was systematically studied as a function of absolute signal level and signal-to-noise ratio. Results indicate that a decrease in the signal-to-noise ratio and a decrease in the sound-pressure level both served to decrease the range of interaural intensity differences over which the invariance occurs. However, while a decrease in both parameters decreased the range of intensity independence, there was a strong interaction between these parameters: The addition of noise eliminated the effect of sound-pressure levels. These findings are discussed in the context of the model described in the companion paper [Yund and Efron, J. Acoust. Soc. Am. 62, XXX–XXX(1977)].