Mary Moore, the time of day lady in Cecil’s column was interviewed for a book on AT&T called something like The Biggest Company in the World which came out before divestitture. I remember it because it had a chapter on the part of Western Electric where I used to work. Mrs. Moore’s daughter did recordings also.
Private companies used these tapes also - Busey Bank in Champaign Illinois had a time service with Ms. Moore’s voice in the late '70s. The voice was unkindly known as the Busey Bitch among students.