Aspiration (phonetics)

In phonetics, aspiration is the strong burst of air that accompanies the release of some obstruents. To feel or see the difference between aspirated and unaspirated sounds, one can put a hand or a lit candle in front of his or her mouth, and say tore and then store. One should either feel a puff of air or see a flicker of the candle flame with tore that one does not get with store. In English, the t should be aspirated in tore and unaspirated in store.

The diacritic for aspiration in the International Phonetic Alphabet is a superscript "h", . Unaspirated consonants are not normally marked explicitly, but there is a diacritic for non-aspiration in the Extended IPA, the superscript equal sign, .

Voiceless consonants are produced with the vocal cords open. (Voicing involves bringing the vocal cords close together.) Voiceless aspiration occurs when the vocal cords remain open after a consonant is released. An easy way to measure this is by noting the consonant's voice onset time, as the voicing of a following vowel cannot begin until the vocal cords close. However, aspirated consonants are not always followed by vowels or other voiced sounds; indeed, in Eastern Armenian, aspiration is contrastive even at the ends of words:

Final aspiration in E. Armenian
pillow
difficult
high

English voiceless stop consonants are aspirated when they are word-initial or begin a stressed syllable, as in pen, ten, Ken, but this is not distinctive. That is, these consonants have unaspirated variants in other positions, such as word-finally or in an initial cluster with [s], as in spun, stun, skunk. In many languages, such as the Chinese languages, Hindi, Icelandic, Korean, Thai, and Ancient Greek, etc. and etc. are different phonemes altogether.

Alemannic German dialects have unaspirated as well as aspirated ; the latter series are usually viewed as consonant clusters. In Danish and most southern varieties of German, the "lenis" consonants transcribed for historical reasons as are distinguished them from their "fortis" counterparts mainly in their lack of aspiration.

Icelandic has pre-aspirated ; some scholars interpret these as consonant clusters as well.

There are degrees of aspiration. Armenian and Cantonese have aspiration that lasts about as long as English aspirated stops, as well as unaspirated stops like Spanish. Korean has lightly aspirated stops that fall between the Armenian and Cantonese unaspirated and aspirated stops, as well as strongly aspirated stops whose aspiration lasts longer than that of Armenian or Cantonese. (See voice onset time.) An old IPA symbol for light aspiration was (that is, like a rotated ejective symbol), but this is no longer commonly used. There is no specific symbol for strong aspiration, but can be iconically doubled for, say, Korean * vs. *. Note however that Korean is nearly universally transcribed as vs. , with the details of voice onset time given numerically.

Aspiration also varies with place of articulation. Spanish /p t k/, for example, have voice onset times (VOTs) of about 5, 10, and 30 milliseconds, whereas English /p t k/ have VOTs of about 60, 70, and 80 ms. Korean has been measured at 20, 25, and 50 ms for /p t k/ and 90, 95, and 125 for .

The word 'aspiration' and the aspiration symbol is sometimes used with voiced stops, such as . However, such "voiced aspiration", also known as breathy voice or murmur, is less ambiguously transcribed with dedicated diacritics, either or . (Some linguists restrict the subscript diacritic to sonorants, such as vowels and nasal consonants, which are murmured throughout their duration, and use the superscript for the murmured release of obstruents.) When it is included as aspiration, voiceless aspiration is called just that to avoid ambiguity.

Reference

*Taehong Cho and Peter Ladefoged, "Variations and universals in VOT". In Fieldwork Studies of Targeted Languages V: UCLA Working Papers in Phonetics vol. 95. 1997.

See also

*Voice onset time
*List of phonetic topics
*Phonation