I think it’s safe to say that this is an effect you won’t find in every guitarists pedal collection. The talkbox really had its heyday in the 1970s in the hands of artists like Peter Frampton when the talking guitar effect was something of a novelty.
I use a Rocktron Banshee amplified talkbox, a solid piece of kit if a little difficult to get used to. In essence the pedal has an internal amplifier and speaker cone the sound from which is directed into a plastic tube. You hold the other end of the tube in your mouth so you can shape the sound by moving your lips and tongue.
The actual sound of the talk box must be captured with a microphone. Although there is an output to direct to an amplifier this will not include the shaped tone which comes from your mouth. To make this work effectively I find I really need a separate boom mike stand to hold the tube. If you attach the tube to stand holding your mike you risk getting rumble and noise from accidental movement of the stand. I also find a separate stand allows me to position the tube better. A word of caution – if you don’t use a stand and try to hold the tube in your mouth if can get very tiring and there’s a good chance your gag reflex will kick in.
To quote Rocktron, “When playing, the sound produced by the driver travels through the tube to the other end, which is held in the players mouth at the microphone. The player manipulates the talkbox sound through mouth movement.”
The sound of the internal amplifier and driver is pretty hideous really. The overdriven sound is very gritty – you probably wouldn’t want to use that sort of sound on its own but it does travel well up the tube.
I’ve recorded a couple of short examples of the Banshee in action. Both were played using an Ibanez JEM recorded using a condenser microphone. The Banshee was set up with the gain knob at about 30% and tone at 50%.
If you are looking for more information about this type of effect the Talkbox FAQ is a great place to start.