Pitch contour shape matters in memory

The Autosegmental-metrical model of prosody [1,2] holds that pitch melodies can be modeled with level low and high tones; information about the shape of the pitch contour is not part of the phonological representation. Yet recent results [3,4] show that contour shape affects the perception of tone height and timing. A pitch plateau that maintains a level pitch at its peak will be perceived as higher and/or having a later accent than a sharp peak of the same height. In this study we ask whether contour shape is encoded in the mental representation of pitch accent by testing memory for the H* pitch accent of American English, realized as a peak or plateau. We establish that, as predicted by recent research, pitch shape affects perception. Then we test these same distinctions in a memory task. Our findings show that pitch plateaus are better discriminated than peaks, and that this advantage grows larger when memory load is higher. We argue that this shows contour shape matters, not just psychoacoustically in immediate perception, but also in memory, and that shape may therefore be posited to be included in the phonological representation of pitch accent.