Sergeant & Welch _Perceived Similarities...'. Photocopy of Desmond S. Sergeant and Graham F. Welch _Perceived similarities and differences in the singing of trained childrens choirs_. Describes an experiment performed at the Roehampton Institute where experts listened to sound recordings of choral singing and could not conclusively state whether they were male or female. Also includes Bernarr Rainbow's draft response, as president of the Campaign for the Defence of the Traditional Cathedral Choir. 1997