are shaped by the mouth, producing a sound very similar to voice, effectively allowing the guitar to appear to "speak". The effect produced by talk boxes and vocoders are often conflated by listeners. However, they have radically different mechanisms for achieving the effect. Talk boxes send the carrier signal into the singer's mouth, where it is then modulated by the singer themselves. On the other hand, vocoders process both the carrier and the modulator signal integrally, producing the output as a separate electric signal. In addition, they are also more common in different genres: a talk box is often found in rock music due to its typical pairing with a guitar, whereas vocoders are almost always paired with synthesizers, and as such, are ubiquitous in electronic music. History Singing guitar In 1939, Alvino Rey, amateur radio operator W6UK, used a carbon throat microphone wired in such a way as to modulate his electric steel guitar sound. The mic, originally developed for military pilot communications, was placed on the throat of Rey's wife Luise King (one of The King Sisters), who stood behind a curtain and mouthed the words, along with the guitar lines. The novel-sounding combination was called "Singing Guitar", and employed on stage and in the movie Jam Session, as a "novelty" attraction, but was not developed further. Rey also created a somewhat similar "talking" effect by manipulating the tone controls of his Fender electric guitar, but the vocal effect was less pronounced. Sonovox Another early voice effect using the same principle of the throat as a filter was the Sonovox, invented by Gilbert Wright in 1939. Instead of a throat microphone modulating a guitar signal, it used small transducers attached to the performer's throat to produce sounds the mouth shapes. The Sonovox was marketed and promoted by the Wright-Sonovox company, an affiliate of the Free & Peters advertising agency. The Sonovox was used in many radio station IDs and jingles produced by JAM Creative Productions and the PAMS advertising agency of Dallas, Texas. Lucille Ball made one of her earliest film appearances during the 1930s in a Pathé Newsreel demonstrating the Sonovox. The first use in music was a score by Ernst Toch in the Paramount Picture "The Ghost Breakers", in June 1940. The Sonovox was used to produce the "voice" of the anthropomorphic train Casey Jr. in the 1941 animated film Dumbo, and was also used for