The concept is really simple and no sophisticated electronics are required. A speaker is attached to a plastic tube that goes in your mouth. You use your mouth to shape the sound and even to put words into your tones. All you need is a talk box, a microphone and an amp, and you can follow in the footsteps of Peter Frampton, Joe Walsh, Slash, Alice in Chains, Aerosmith, Sly and the Family Stone and many others who have found this simple device at terrific source of creativity.
The Dunlop HT1 Heil Talk Box is the original and still the champ.
Talk Box vs. Vocoder
The Talk Box is not to be confused with the Vocoder. A vocoder is a very cool piece of electronics that processes your voice producing robotic style voice effect, auto tuning, and other interesting effects.
The Electro Harmonix V256 Vocoder Guitar features “Reflex Tune” which adds pitch correction (most famously used by Cher in "Believe (in life after love)." It can also weld your voice to your guitar, for a talk box effect, and features a gender bender to make voices sound more male or female. The V256 also gives you 3 robotic voices and drones with pitch control.
Some other vocoders, built into synth keyboards include the Korg microKorg XL, the Korg microKorg XL 37 Key Pro Keyboard, and the Novation Ultra Nova.