Vowel reduction


 * Not to be confused with Vowel reduction in the context of historical linguistics.

Vowel reduction is the term in phonetics that refers to various changes in the acoustic quality of vowels related to changes in stress, sonority, duration, loudness, articulation, or position in the word (e.g. for Creek language ). Vowel reduction is one of the sources of distinction between a spoken language and its written counterpart.

The term "vowel reduction" is also applied to differences in a language variety with respect to, e.g., the language standard.

A well-researched type of reduction is that of unstressed vowels, which in many languages leads to "neutralization" of acoustic distinctions of vowels. The most common example is the schwa sound, present in many languages.

Sound duration is a common factor: in a fast speech vowels are reduced due to physical limitation of articulatory organs, e.g., the tongue cannot move in a proper position on time to produce a full-quality vowel. Compare: clipping (phonetics).

Vernacular and formal speeches usually have different levels of vowel reduction.

Different languages have different types of vowel reduction, and this is one of difficulties in language acquisition; see, e.g., "Non-native pronunciations of English" and "Anglophone pronunciation of foreign languages". Vowel reduction of second language speakers is a separate study.

Some languages, e g., Finnish, Hindi and classical Spanish, are claimed to lack vowel reduction, whereas Mexican Spanish does exhibit it.

Historically, stress-related vowel reduction is a principal factor in the development of Indo-European ablaut.

Language-specific

 * Vowel reduction in English
 * Vowel reduction in Russian