A UK toddler born deaf can now hear unaided, after a groundbreaking gene-therapy treatment. Opal Sandy was treated shortly before her first birthday – and six months on, can hear sounds as soft as a whisper and is starting to talk, saying words such as “Mama”, “Dada” and “uh-oh”. Given as an infusion into the ear, the therapy replaces faulty DNA causing her type of inherited deafness. The trial is recruiting patients in the UK, US and Spain.