Cross-modal correspondence between vibrations and colors

Participants matched a color to a vibrotactile stimulus of 1 s duration on the palm of the hand. Stimuli were combinations of one of six frequencies (10–200 Hz) and four amplitudes (10–40 dB SL). Color choices were converted to lightness, chroma, and hue angle values defined in the CIELAB color space. Results showed that the color chroma increases with the increase in vibratory amplitude, with no effect of vibration frequency. Lightness was not significantly modulated by the vibratory variables. Histograms of color hue showed three main peaks (violet, red and green) in participants' responses. The pattern was for low-frequency vibrations (1035 Hz) to evoke the violet color hue at low amplitudes and the red color hue at high amplitudes, whereas high-frequency vibrations (60–200 Hz) evoked the green color hue with some trace of the red color hue at high amplitudes. The results are discussed for designing colorful experiences using vibrotactile feedback.