Flapping or tapping, also known as alveolar flapping, intervocalic flapping, or t-voicing, is a phonological process found in many varieties of English, especially North American, Cardiff, Ulster, Australian and New Zealand English, whereby the voiceless alveolar stop consonant phoneme is pronounced as a voiced alveolar flap, a sound produced by briefly tapping the alveolar ridge with the tongue, when placed between vowels. In London English, the flapped is perceived as a casual pronunciation intermediate between the "posh" affricate and the "rough" glottal stop. In some varieties,, the voiced counterpart of, may also be 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 may be pronounced as a nasalized flap, making winter sound similar or identical to winner.