In 1997, Bella Bathurst began to go deaf. Within a few months, she had lost half her hearing, and the rest was slipping away. 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. She investigates the science behind deafness, hearing loss among musicians, soldiers and factory workers, sign language, and what the deaf know about these subjects that the hearing don't.