Also known as sound photism, sound-seeing, and chromatic-phonemic synaesthesia. The term phonopsia comes from the Greek words phonème (voice, sound) and opsis (seeing). It is used in * synaesthesia research to denote a hallucinated sound triggered by a regular visual percept.
References
Quercy, P. (1930). L'hallucination. Tome2. Études cliniques. Paris: Librairie Félix Alcan.
Dictionary of Hallucinations. J.D. Blom. 2010.