The human brain was wired for speech, and now machines are being built to take advantage of that. Nass has discovered that even crude computer speech can trigger a profound human response we so want to believe those voices are real. Can we use that response to improve machine-human communication? Would a female-sounding computerized physics tutor encourage more women to become physicists? Can a car's navigation system encourage you to drive more safely? Or might it irritate you enough to provide a dangerous distraction? Nass has the data.