Young female voices. Flustered and looking for help. Apparantly no males in the area, certainly no male voices in earshot. These recordings tap into some base instincts within the mostly male scammers. I suspect that a recording of my voice wouldnt keep them on the line nearly as long.

But for these scammers i'd go with something more targeted: old people. Thier prefered prey is flustered old people who dont understand computers. Give them an old woman with bad hearing who mumbles about her internet not working. Then toss in a few "do you take visa" and some random numbers. That will keep them on the hook.