Ideasthesia vs synesthesia

Ideasthesia

While “synesthesia” meaning “union of senses” implies the association of two sensory elements with little connection to the cognitive level, empirical evidence indicated that most phenomena linked to synesthesia are in fact induced by semantic representations. – from Wikipedia

Synesthesia

There are two overall forms of synesthesia:

projective synesthesia: people who see colors, forms, or shapes when stimulated (the widely understood version of synesthesia).
associative synesthesia: people who feel a very strong and involuntary connection between the stimulus and the sense that it triggers. – from Wikipedia