How does Peter Frampton do that thing with the guitar that makes his voice distorted?

is it a special pedal or something?

That weird 'talking guitar' sound you can hear on 'Show Me The Way' is produced by a gadget called the 'TalkBox', that Peter first came across in 1971 when he heard a pedal steel player using it on the sessions for George Harrison's 'All Things Must Pass'. Peter was so impressed that he found out where he could get one from - a company called HEIL Sound in California made and marketed them. Peter got his first one in 1974 and has been using one live since then!

The first poster is correct. I originally thought he was playing the guitar like that...boy how stupid was I. If you watch him play, you can see him singing intot he microphone the exact words.