Flapping

Flapping or tapping, also known as alveolar flapping, intervocalic flapping, or t-voicing, is a phonological process involving a voiced alveolar tap or flap; it is found in many varieties of English, especially North American, Cardiff, Ulster, Australian and New Zealand English, where the voiceless alveolar stop consonant phoneme /t/ is pronounced as a voiced alveolar flap [ɾ], a sound produced by briefly tapping the alveolar ridge with the tongue, when placed between vowels. In London English, the flapped [ɾ] is perceived as a casual pronunciation intermediate between the affricate [tsʰ], with higher class associations, and the glottal stop [ʔ], with lower class associations. In these named varieties, outside of Britain, /d/, the voiced counterpart of /t/, is also frequently pronounced as a flap in such positions, making pairs of words like latter and ladder sound similar or identical. In similar positions, the combination /nt/ may be pronounced as a nasalized flap [ɾ̃], making winter sound similar or identical to winner.

Flapping of /t/ is sometimes perceived as the replacement of /t/ with /d/; for example, the word butter pronounced with flapping may be heard as "budder".

In other dialects of English, such as South African English, Scottish English, some Northern England English (like Scouse), and older varieties of Received Pronunciation, the flap is a variant of /r/ (see Pronunciation of English /r/).