On Thursday, All Things Considered ran a piece on synthetic voices, sort of like the ones in the promo for this site. Here’s a clip from ATC where Robert Siegel learns how to create a voice from existing speech.

SIEGEL: How do you go about doing this? How do you create a voice?

Dr. AYLETT: To a certain extent, the methodology is fairly straightforward. You take a lot of audio from a speaker. You then cut that up into tiny little pieces. Each piece is a little sound. So for example, cat would be made up of three sounds, /k/, /a/, and /t/.

In order to then produce a new sentence, you then take those sounds, you rearrange them, and you stick them back together again.

SIEGEL: But you would need an awful lot of sound of one voice to do that.

Dr. AYLETT: Not as much sound as you might think because although there are hundreds and thousands of words, within English, there are only about 45 different sounds.

Listen to the whole interview here.