Sound Properties Associated With Equiluminant Colours

Abstract

There is a widespread tendency to associate certain properties of sound with those of colour (e.g., higher pitches with lighter colours). Yet it is an open question how sound influences chroma or hue when properly controlling for lightness. To examine this, we asked participants to adjust physically equiluminant colours until they ‘went best’ with certain sounds. For pure tones, complex sine waves and vocal timbres, increases in frequency were associated with increases in chroma. Increasing the loudness of pure tones also increased chroma. Hue associations varied depending on the type of stimuli. In stimuli that involved only limited bands of frequencies (pure tones, vocal timbres), frequency correlated with hue, such that low frequencies gave blue hues and progressed to yellow hues at 800 Hz. Increasing the loudness of a pure tone was also associated with a shift from blue to yellow. However, for complex sounds that share the same bandwidth of frequencies (100–3200 Hz) but that vary in terms of which frequencies have the most power, all stimuli were associated with yellow hues. This suggests that the presence of high frequencies (above 800 Hz) consistently yields yellow hues. Overall we conclude that while pitch–chroma associations appear to flexibly re-apply themselves across a variety of contexts, frequencies above 800 Hz appear to produce yellow hues irrespective of context. These findings reveal new sound–colour correspondences previously obscured through not controlling for lightness. Findings are discussed in relation to understanding the underlying rules of cross-modal correspondences, synaesthesia, and optimising the sensory substitution of visual information through sound.

The typology of sound symbolism: Defining macro-concepts via their semantic and phonetic features

“…To begin with, we included all of the 56 fundamental oppositional concepts that were shown to have great sound symbolic potential by Johansson (2017), mostly based on proposed lexical universals (Dixon 1982;Goddard 2001;Goddard & Wierzbicka 2002;Koptjevskaja-Tamm 2008;Paradis et al 2009 Associations between colors and sounds are perhaps among the most commonly studied sound symbolic areas. Even though synesthetes experience these associations more strongly than non-synesthetes (Ward et al 2006), hue, chroma and lightness are also associated with auditory frequency and loudness (Spence 2011;Walker 2012;Hamilton-Fletcher et al 2017) and other senses, such as touch (Ludwig & Simner 2013), in the general population. What is more, Berlin and Kay (1969) famously demonstrated strong cross-linguistic regularities in the lexicalization patterns of monolexemic color terms.…”

Implicit associations between individual properties of color and sound

“…Pitch – the property describing how “high” or “low” a tonal sound appears to be – is reliably associated with luminance (Hubbard, 1996; Marks, 1974; Mondloch & Maurer, 2004; Ward, Huckstep, & Tsakanikos, 2006) and perhaps also with saturation (Hamilton-Fletcher, Witzel, Reby, & Ward, 2017; Ward et al, 2006). Unlike loudness, pitch is usually considered a metathetic rather than a prothetic dimension (Spence, 2011), in the sense that higher pitch is not “larger” or “greater” than low pitch, but qualitatively different.…”

Cross-modal association between vowels and colours: A cross-linguistic perspective

“…A wider choice of colour would allow a more comprehensive investigation. Second, some recent studies used objective measures to determine lightness/luminance of the colours (e.g., Moos et al, 2014;Hamilton-Fletcher et al, 2017), while we did so subjectively by asking the participants to rate the lightness of the colours. Although we believed that subjective lightness as perceived by the participants would allow us to assess the effects of lightness perception more directly, more objective measurements of the presented colours' luminance as measured by a chromameter can corroborate our findings.…”

“…The CIE coordinates were converted into CIELUV coordinates resulting in L* (luminance), u* (red-green), and v* (yellow-blue). Doing so enabled them to disentangle luminance and hue (e.g., Hamilton-Fletcher et al, 2017). They found significant influence of F1 and F2 on colour association: a higher u* (redder) correlates with decreasing F2 and particularly strongly with increasing F1 (i.e., /a/).…”