But rdl said "using telephone in general" (which I assume was meant in the context of speaking with customers) and people do that even if they weren't hired specifically for communicating.
Yeah, I didn't really mean "as a telephone end user"; I meant "in a professional telephone-based job, especially one in data entry", although I'd consider it to be one of the basic communications skills people should learn just as people, too.
It was chosen specifically to work through bad communications channels and diverse accents, especially if you use the specific pronunciations required for the words (kay-beck for quebec, etc.).