According to Science Daily, …”there are people who can smell sounds, see smells or hear colours. One person out of every thousand has synesthesia, a psychological phenomenon in which an individual can smell a sound or hear a color. Most of these people are not aware they are synesthetes: they think the way they experience the world is normal.”
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In the context of this blog, all sorts of questions come up, which I will let you infer on your own.