I get cold calls from time to time about tech stuff. Usually staffing agencies. Just got one today on voice mail and the caller had such a thick Indian accent that it took me 30 seconds to figure out what he was calling about. A good principal in cold calling would be to make sure the person doing the call has a voice like a radio announcer. Communication is all you have going for you at the start of a cold call, so the voice (and accent) are about the most important thing in the first few seconds.