Closing phase

During the closing phase, two articulators are brought together to form a complete closure behind which air will be trapped. The action of forming a closure does not last long: typically no more than a few tens of milliseconds.

As the articulators move to form the closure, the shape of the vocal tract is changed. Acoustically, changes in shape of the vocal tract lead to changes in its natural resonances, and so it is possible to hear both that a closure is being made and where the closure is being made.

These movements into closure can be heard if you produce sequences of vowel + plosive, but hold the closure and do not release it. Try saying ‘nab’ but once the lips are together, do not separate them. Try the same with ‘had’ and ‘hag’. You should be able to hear that the vowels end differently for each place of articulation. The difference is slight, so you will need to listen carefully.