:Voice onset time:

Often abbreviated to VOT. The period of time from the burst of a plosive to the onset of vocal fold vibration. In negative VOT (also called voicing lead) the onset of vocal fold vibration occurs before the plosive burst). In zero VOT, the burst and voicing onset are more or less simultaneous. In positive VOT (also called voicing lag) there is an appreciable delay after the burst before the vocal folds start vibrating. VOT is a major cue to the voicing status of plosives. Languages divide the VOT continuum in different ways to signal voicing. For example, French voiced plosives usually have negative VOT and the voiceless ones zero VOT. In most varieties of English voiced plosives have zero VOT and voiceless ones an appreciable positive VOT.