Glottal stop

The glottal stop is a type of consonantal sound used in many spoken languages, produced by obstructing airflow in the vocal tract or, more precisely, the glottis. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ʔ⟩.

In English, the glottal stop is represented, for example, by the hyphen in uh-oh!. For most United States English speakers, a glottal stop is used as an allophone of /t/ between a vowel and "m" (as in atmosphere or Batman) or a syllabic "n" (as in button or mountain), except when talking slowly. In British English, the glottal stop is most familiar in the Cockney pronunciation of "butter" as "bu'er".