Aspiration (from Latin aspirare " air breathe out ", also aspiration ) in phonetics means that a sound, usually a plosive, is accompanied by a puff of air. In the IPA phonetic transcription it is marked by a superscript "h" ( ʰ ).
In the German standard pronunciation are the unvoiced plosives p, t, k aspirated in most positions, [alt k ʰ ʰ ] eg in cold. In High German the aspiration is, however, an adjoint, not a distinctive feature, in other words, it is not crucial to distinguish the sound from another. In contrast, however, in some southern German dialects: Here b, d, g as [ p ], [ t], are spoken [k ] ( unaspirated ) and of p, t, k can only be distinguished by their aspiration. The aspiration here is thus quite phonematically. The same is true for example in the Indo-Aryan languages , Armenian, Korean or Thai. Even in the ancient Greek language the letters were φ, θ and χ spoken originally aspirated, which is still in the growing acceptance that they are reproduced in foreign words with ph, th, and ch.
Aspiration usually affects voiceless plosives, get into the Indo-Aryan languages but in addition also voiced -aspirated plosives, eg [ b ʱ ] before. Some Indo-Aryan languages have also aspirated liquids, Hindi about the aspirated voiced retroflex flap [ ɽ ʰ ].
In some German accents and dialects is in contrast to the standard pronunciation no aspiration of unvoiced consonants instead, such as in the northern Rhine. Also no aspiration have many standard European languages such as French or Spanish.
The aspiration as Phonationstyp of vowels is referred to in English as a breathy voice.