Alex BowersMath 5Professor Barnett05/30/07The Talk BoxI suppose I’ve always been interested in the talk box, a device which enables an individual to impose phonetic sounds on the signal from a musical instrument, such as a guitar or keyboard. Whenever I hear Peter Frampton’s “Do You Feel like We Do” on any number of generic classic rock radio stations, I always think to myself, “hey, that’s pretty cool. I wonder how he does that,” and then briefly daydream about someday being able to talk like a robot myself. Well, those daydreams have become a reality as I have recently completed the construction of my own talk box, and while I may still be a rather mumbling robot (I’ve only been practicing for a couple days), I still feel pretty cool, albeit in a gimmicky-Peter-Frampton-esque sort of way. I think, however, that my aspirations to becomea talk box master are more inspired by Stevie Wonder, another music legend to use the talk box, as my primary musical instrument is the piano, and my guitar skills are mediocre at best.But, thus is the great versatility of the talk box. It can be used with just about any musical instrument that produces an electric signal to create an astoundingly vast array of tonal effects for such a device of its simplicity.The talk box is a surprisingly simple device (even I was able to build one). It operateson the same basic premise of human speech, only instead of the sound originating in one’s vocal cords, it originates from the musical instrument and is sent through an amplifier, into a speaker and through a length of tubing into the mouth, thereby allowing the musician to manipulate the original instrument signal by altering the shape of the mouth. In essence, the talk box enables the musician to impose the formants of a particular mouth shape onto the input signal of the instrument and thereby give it almost speech-like qualities. This is often referred to as the “talking guitar” effect and has become increasingly popular in modern music across a number of genres from rock and roll to funk to hip hop.It was difficult to find reliable information about the history of the Talk Box, as the only information I could find came from either wikipedia.com entries or personal web pages. According to Wikipedia, the talk box was invented in 1971 by Bill West, wife of country music artist Dottie West, for Joe Walsh to play "Rocky Mountain Way" live. Joe Walsh, then a solo artist, would go on to join the Eagles as lead guitarist. Another site I found, however, says that Bob Heil, of Heil Sound, invented the device for Walsh, and then later “brought it toprominence with Peter Frampton’s Show Me The Way album.” According to the wiki article, Heil patented the talk box and in 1973 gave it to Frampton as a Christmas present. Both accounts seem somewhat suspect, though, as I couldn’t find any other information to support the claim that Bill West invented the talk box, nor is there a Peter Frampton album called Show Me The Way. Frampton used the talk box on the song “Show Me the Way” on his 1976 release live album Frampton Comes Alive! What I do know, is that Heil was the first to patent and manufacture the talk box, and while it is presently sold by Dunlop (Heil sold the manufacturing rights in 1988), it is still marketed and labeled as the “Heil Talk Box.” Other models have been made and manufactured throughout the years, including the Electro-Harmonix (E-H) Golden Throat, the Kustom Bag, and the currently distributed models the Rocktron Banshee and the Danelectron Free Speech Talk Box.Frampton also produces a line of his own “Framptones” which are described on his website as having “a majestic, pyramid-shaped, powder coated steel chassis” among other features. Another interesting device I discovered while researching the talk box is a device which preceded it known as the Sonovox, which consisted of two small loudspeakers that attached to the outside of the musicians throat, thereby sending vibrations through the vocal chords. The talk box has been used by numerous musicians throughout the past few decades of its existence. As I mentioned, it was first used by Joe Walsh, and then by artists such as Peter Frampton and Stevie Wonder. Other artists who have used the talk box include Aerosmith’s Joe Perry on “Walk This Way” and “Sweet Emotion,” Jerry Cantrell of Alice in Chains on “Man in the Box,” Slash of Guns N’ Roses on a number of songs, Richie Sambora of Bon Jovi on “Its My Life” and “Living on a Prayer” as well as many others, funk legend Bootsie Collins, David Gilmour of Pink Floyd, Jeff Beck, Steely Dan, The Doors, Carlos Santana, moe., Foo Fighters, The Flaming Lips, and Snoop Dogg, just to name a few. The full list is quite impressive. It seems that I’m not the only one who has daydreamed about following in Peter Frampton’s shoes. Now that we have a pretty good idea of the talk box’s history, the question which immediately presents itself is how does it work? In order to fully answer this question, it is necessary to have an understanding of how human speech operates, specifically, the source-filter model. According to the source-filter model theory, human speech consists of the combination of two primary elements, a source of sound (i.e. air from the lungs passing over the vocal chords) and a filter (i.e. the vocal tract, or mouth, tongue, jaw, lips etc.) which modifies the source sound by variation in shape.In normal speech, the vocal chords, or vocal folds as they are also referred to, oscillate between open and closed at varying frequencies to produce a periodic signal of pressure pulses which travel into the vocal tract. The frequency of this periodic signal is whatdetermines the pitch of the resulting sound. It is a spiky signal, or in other words, it contains many high harmonic partials. It is these harmonic partials which allow the vocal tract to so easily manipulate the source sound to create speech sounds of varying timbre which we can easily identify as vowels, consonants, words, phrases, etc. Since the vocal tract operates like a closed-open pipe system, there are various nodes and antinodes throughout which can either be emphasized or muted by the shape of the mouth. Each of these nodes has a corresponding resonant frequency, or a frequency which is naturally excited by the activation of its respective node. When a node is pinched, or narrowed, the resonant frequency will