Imagine being able to ‘taste’ every word that comes out of your mouth. Everything you or someone else says provoking something in your brain to kick your taste buds into action. It sounds incredulous, but for a tiny proportion of the world’s population, that is their reality. It’s a neurological phenomenon called synaesthesia, where two or more senses merge. Tamasin Ford meets two sisters from Glasgow, Scotland, who have had the condition for as long as they can remember. They share what it’s like to live with this explosion of taste at every waking moment. But how and why does it happen? We try to unpick the science behind it and take a look at what synaesthesia could tell us about how we experience taste and flavour. If you would like to get in touch with the show, please email thefoodchain@bbc.co.uk (Picture: Keyboard letters in a soup bowl. Credit:Getty/BBC) Contributors: Julie McDowall and Jennifer McCready Guy Leschziner, author and Professor of neurology and sleep medicine at King's College London.