In phonology, tenseness or tensing is the pronunciation of a vowel with a relatively longer duration and with the tongue positioned slightly higher and less centralized in the mouth compared with another vowel, thus causing a phonemic contrast between the two vowels. Contrast between vowels on the basis of tenseness is common in many languages, including English; for example, in most English dialects, (as in the word beet) is the tense counterpart to the lax (as in bit), and (as in kook) is the tense counterpart to the lax (as in cook). The opposite quality of tenseness, in which a vowel is produced as relatively more shortened, lowered, and centralized, is called laxness or laxing.