On Associations of Light and Sound: The Mediation of Brightness, Pitch, and Loudness

The results mimic those of synesthesia and suggest that most subjects may match auditory to visual brightnesses, but the system that mediates these cross-modal equivalences is unknown.

Abstract

Subjects searched for pure tones to match the brightnesses of gray surfaces. Nearly all repeatedly set increasing pitch to increasing brightness; some set increasing loudness to increasing brightness, while others set it to increasing darkness; and most, when brightness was held constant, offset increasing pitch by decreasing loudness. The results mimic those of synesthesia and suggest that most subjects may match auditory to visual brightnesses. The system that mediates these cross-modal equivalences is unknown but may best be thought of as a cognitive mechanism that is capable of manipulating dimensions of sensory experience.