Transcription Service - Requires Excellent English

I'm look for an assistant to transcribe recorded conversations into a word document. This requires a very good ability to both understand the English language and to transcribe it accurately - and of course, very good typing skills. A lot of the conversations are with engineers, mechanical or electrical, so a familiarity with engineering, mechanical systems (such as hot water boilers), HVAC or electrical systems (transformers, power stations) would be a plus. I would expect a 1 to 2 day turnaround of work. *Must be a very good communicator* - someone who responds to emails in a prompt fashion.