The declination effect

Abstract

The perception of the declination effect, which is the nearly universal tendency of intonation to drift downward in pitch, was investigated. The perception of this effect is interesting because it exemplifies the general problem of how the moving pitches used in intonation are processed and remembered. The stimuli for the experiments were nonsense sentences of the form “ma MA ma ma MA ma.” The pitch on one stressed syllable was varied by small increments and the resynthesized stimuli were randomizod before presentation. Subjects judged which peak was higher in pitch. A second peak with the same pitch as the first generally sounded higher. This demonstrated that the declination effect is psychologically real. The crossover point, or point of subjective equality, for wide pitch range stimuli reflected the large declination effect found in animated speech, whereas a negligible effect was found for narrow pitch range stimuli. A 3.6-dB increase in amplitude on the second stressed syllable shifted the crossover point downward to a surprising degree. Raising the pitch on the unstressed syllables made the second stressed syllable sound lower. [Work carried out at Bell Laboratories.]