DSP - Digital Signal Processing
DSP is particularly useful for voice communications in high-noise, industrial and motorsport communications where it improves speech quality under high noise conditions.
Digital Signal Processing is a term used to cover many forms of electronic processing but in voice communication is used to refer to circuits and software that improves the voice audio.
All Digital radios have DSP as standard.
DSP works by a digitising your voice and processing it with sophisticated software which recognises the human voice and filters out non human noise such as wind, machine and other ambient non-speech sounds. The processed speech is returned as clearer audio for transmission by the radio.