Haptic and sound correlations: pitch, loudness and texture

People process information through multiple modalities and many studies have been done that show interaction among the auditory, haptic and visual modes. This paper reports on a correlation between the haptic property of roughness and each of the audio properties of pitch and loudness. There were four experiments: given a roughness, match a loudness level to it and vice versa and given a roughness, match a pitch to it and vice versa. Subjects showed a strong correlation in the first two experiments, associating louder sounds with rougher textures and softer sounds with smoother textures. They also showed, although not always in the same direction, a strong correlation between pitch (high/low) and roughness. Applications of this study are to multimodal user interfaces and to music cognition.