another book, by Nora Ellen Groce, about deafness on the island of Martha’s Vineyard. A sea captain and his brother from Kent, it seems, had settled there in the 1690s; both had normal hearing, but both brought with them a recessive gene for deafness. In time, with the isolation of the Vineyard, and the intermarriage of its close community, this gene was carried by the majority of their descendants; by the mid-nineteenth century, in some of the up-island villages, a quarter or more of the inhabitants were born totally deaf.

