I’ve got grapheme→colour and sound→colour synaesthesia, and some other, weaker associations. Never really examined it too deeply until my teens, when I started noticing some of the features stated in the article, such as a strong ability to distinguish and mimic foreign sounds, recognise and draw faces, and distinguish absolute pitches. It has its pros and cons—I’m pretty easily overwhelmed, for one thing.

If you want to experience synaesthesia firsthand, many people report synaesthetic experiences when taking psychedelics. Being accustomed to that kind of sensory cross-talk, I find it really enjoyable to heighten it, but if you’re new to the feeling, you may find it difficult.