Voicing and plosives in English

English phonology recognizes two sets of plosives, ‘voiced’ /b d g/ and ‘voiceless’ /p t k/, as in pairs such as ‘pit’ – ‘bit’, ‘rapid’ – ‘rabid’, ‘locking’ – ‘logging’, ‘hat’ – ‘had’. These labels are not so helpful from a phonetic perspective, because they hide the complexity of the relationship between voicing, closure and release.

Vowels before [p t k] are regularly shorter than vowels before [b d g]: compare the vowels of ‘lock’ and ‘log’ (e.g. ) or ‘heat’ and ‘heed’ ().

There are many permutations of voicing and closure. There can be voicing throughout the hold phase, within constraints. Voicing can stop before, at or after the closure is achieved; and start again at or after release. Some possible arrangements are illustrated in Figure 7.3.

The time between the release and the onset of voicing is called voice onset time (VOT). It is measured in milliseconds (ms). If the voicing starts after release, VOT is said to be positive, while if it starts before release, it is said to be negative.