Voice activity detection (VAD) occurs in speech processing of computers or other automated or audio systems. It is simply a computational method that allows computers to tell the difference between human speech and background noise or silence. Reproducing the brain's ease of speech recognition is no small feat for a computer. VAD triggers in the presence of speech in order to work with other applications such as speech coding and speech recognition. These processes work together to assist in digital and real-world applications, and facilitate smooth interactions between automated systems and the people that rely upon them.
Electronic reproduction of sound is notoriously incapable of distinguishing what is actually making the sound. Technology often interprets input from multiple sources as a single messy signal. Voice activity detection, or speech detection, benefits numerous applications, including audio and telecommunications signal processing. Relying upon the digital transmission and storage of audio data, VAD encodes and analyzes speech signals with intelligent processing. It is designed to recognize the complex wavelengths of vocal signals and discrete words, which the human brain does easily within its native language and much less easily with acquired languages.
With the advent of digital telecommunications, bandwidth optimization became an area of concern for numerous industries. Voice activity detection decreases errant signaling to reduce bandwidth waste, by transmitting audio occurrences more selectively. Speech creates a messy amplitude that processors must pick through in order to optimize telecommunication resources. This is necessary for processors to better use bandwidth that might otherwise be wasted on noise. Such practices greatly improve telecommunications network effectiveness when multiplied across the sometimes vast network demands of high-speed digital communications.
Speech recognition technology not only assists in communications, but also is useful for digital hearing aid devices. Noise reduction techniques, like minimizing front-end clipping, have benefited applications in countless contexts. Others include mobile communication services and real-time speech transmission over the Internet using voice over Internet protocol VoIP. Telephony relies on voice activity detection for greater clarity and efficiency in digital signal transmissions. It also provides speech enhancements for noisy environments.