The Vocoder was developed in 1928 by Bell Labs, the original use was to reduce bandwidth of voice information so it can travel further distances. They were not used for this however, they were used to send encoded messages during the WWII. A Vocoder works by modulating a sound, mostly used for vocals. Vocoders became popular in music in the 70's by artists such as Kraftwerk, Boney M. and Wendy Carlos. It also became popular in modern music by artists such as Daft Punk, Beastie Boys and Zedd.