In the larynx are the ‘vocal cords’. In their quiescent state, these are relaxed and relatively far apart, leaving a passage so wide that air can pass through almost noiselessly. Speech sounds produced with the cords in this position are ‘voiceless’. […] the vocal cords can be stretched taut, with little space between them, but so held that the passing air stream forces itself through and sets the cords into vibration, like a reed. This vibration is ‘voice’ or ‘voicing’, and speech sound which involve voicing are ‘voiced’.
- Hockett (1958), a pag.64-65