Although this form of synesthesia was documented as early as the 1890s (Flournoy 1893; Calkins 1893) researchers have, until recently, paid little attention to this form (see History of synesthesia research).
儘管這種型式的聯覺早在 1890 年代就有記載（Flournoy 1893；Calkins 1893），直到最近，研究人員對這種型式的聯覺卻甚少關注（參見 聯覺研究史）。