Comment by sremani

If people have never seen you, they make a mental image of you based solely of your voice. If you are working the phones there are certain things you can do to make their mental image of you very positive and in this familiar and authoritative tone gets you high scores and in return positive responses.

If your target audience is a median American, having an American accent will help you, if that is the only parameter that you can improve on.

The Wolf of Wallstreet guy has an entire book on this about his method of phone salesmanship. It's a good read.