In 1997, Bella Bathurst began to go deaf. Within a few months, she had lost half her hearing, and the rest was slipping away. She wasn't just missing punchlines, she was missing most of the conversation - and all of the jokes. For the next twelve years deafness shaped her life, until, in 2009, everything changed again. 'Sound' draws on this extraordinary experience, exploring what it is like to lose your hearing and - as Bella eventually did - to get it back, and what that teaches you about listening and silence, music and noise.