As I earn most of my living as an opera critic and find the human voice as beautiful as any work of art or nature, I suppose it isn’t surprising that I cosset my hearing neurotically. I feel I would kill myself if I developed tinnitus; emergency sirens are the bane of my life; rock concert amplification terrifies me; and, with middle age, straining to catch words at noisy parties and in restaurants has become a real headache.

For such reasons, I found Bella Bathurst’s book terrifying, absorbing and ultimately uplifting. It’s a hymn to the faculty of hearing by someone who had it, lost it and then found it again, written with passion and intelligence and full of matters auricular that I knew little about. It’s a brave and important work.

Hearing, Bathurst explains, is among the great unknowns of the human body, a process both mechanical and electrical activated by way of tiny bones set so deep inside the skull that scans reveal little. Surgery on the inner ear is impossible, most diagnosis is guesswork and the hair cells lining