Voice Quality Perceptions by Synaesthetes, Phoneticians and Controls

Voice-induced synaesthesia is an under-researched neurological condition which leads to multisensory perceptions while hearing someone’s voice. This paper is the first attempt to analyse acoustically which aspects of voice qualities (VQs) trigger consistent colour perceptions and associations in synaesthetes, phoneticians and control participants. An online experiment revealed that f0 influenced brightness and colour associations with the voice for all groups and showed some idiosyncratic patterns for synaesthetes and others for phoneticians. Synaesthetes, for example, were less influenced by f0 in their colour associations than others and phoneticians used scales for high-low and tense-relaxed according to the perceived f0 and VQ more systematically than others. A steeper spectral tilt triggered smoother, softer and more relaxed associations with the voice. A short ABX voice comparison task illustrated that overall voice recognition was similar amongst groups but synaesthetes outperformed controls in recognising a speaker in whisper.