Editing Vocoder Development (section)

== Introduction ==
A vocoder is a crucial component in the realm of speech synthesis, employed in various applications ranging from telecommunications and entertainment to assistive technologies and virtual assistants. Its ability to analyze and synthesize the complex spectrum of human speech, including the pitch, formants, and prosody (melody, rhythm, and intonation in speech), has changed how we use synthesized voices. 

First emerged in the 1930s, the term "vocoder" is derived from "voice" and "coder", and was initially conceived for telecommunication purposes. In the 1950s, Lincoln Laboratory conducted research on detecting pitch in speech, which subsequently influenced the development of voice coders, commonly known as vocoders. These devices are designed to decrease the amount of bandwidth required for transmitting speech. This reduction in bandwidth offers two advantages: it reduces the cost of transmitting and receiving speech, while also enhancing the potential for maintaining privacy.<ref name=":0">Gold, B. (1990). A history of Vocoder research at Lincoln Laboratory. ''The Lincoln Laboratory Journal'', ''3''(2), 163-202.</ref>

Initially, a vocoder described a device designed to compress speech for efficient transmission over telephone lines. The idea involved splitting speech into parts using filters and then reconstructing it on the other end. The goal was to save bandwidth, but in practice,  early vocoders faced challenges in preserving the natural quality of speech. Additionally, the original vocoder only transmitted loudness, not sound quality<ref name=":1">Gordon, J. W., & Strawn, J. (1987). ''An introduction to the phase vocoder'' (No. 55). CCRMA, Department of Music, Stanford University.</ref>.

As technology advanced, the phase vocoder emerged, preserving both the loudness and sound quality of speech. The phase vocoder is a significant advancement in vocoder technology and plays a pivotal role in modern speech synthesis and audio signal processing. It was developed to address critical limitations in early vocoders and revolutionized the way we process and manipulate audio signals. <ref name=":1" />