In phonetics, a continuant is a speech sound produced without a complete closure in the oral cavity, namely fricatives, approximants and vowels. While vowels are included in continuants, the term is often reserved for consonant sounds. Approximants were traditionally called "frictionless continuants". Continuants contrast with occlusives, such as plosives, affricates and nasals. Compare sonorant (resonant), which includes vowels, approximants and nasals but not fricatives, and contrasts with obstruent.