I came across this passage last night in Seeing Voices, an Oliver Sacks book about the history of the deaf, their struggle for acceptance in the world of the hearing and the development of Sign language. In his book Sack relates a fascinating story from Nora Ellen Groce's Here Spoke Sign Language: Hereditary Deafness on Martha's Vineyard.
Through a mutation, a recessive gene brought out by inbreeding, a form of hereditary deafness existed for 250 years on Martha's vineyard, Massachusetts, following the arrival of the first deaf settlers in 1690s. By the mid nineteenth century, scarcely an up-land family was unaffected, and in come villages, the incidence of deafness had risen one in four. In response to this, the entire community learned Sign, and there was free and complete intercourse between the hearing and the deaf. Indeed, the deaf were scarcely seen as "deaf" and certainly not seen as being at all handicapped.In astonishing interviews recorded by Groce, the island's oldest residents would talk at length, vividly and affectionately about their former relatives usually without even mentioning that they were deaf. And it would only be if this question was specifically asked that there would be a pause and then, "Now you come to mention it, yes, Ebenezer was deaf and dumb." But Ebenezer's deaf and dumbness had never set him apart, had scarcely been noticed as such; he had been seen, he was remembered, simply as "Ebenezer"- friend, neighbor, dory fisherman- not as some special handicapped, set-apart mute. …Intriguingly, even after the last deaf Islander had died in 1952, the hearing tended to preserve Sign among themselves, not merely for special occasions but generally. They would slip into it, involuntarily, sometimes in the middle of a sentence, because Sign is "natural" to all who learn it as a primary language and has an intrinsic beauty and excellence sometimes superior to speech.
Seeing Voices, by Oliver Sacks