Approximant

Type of speech soundApproximants are speech sounds that involve the articulators approaching each other but not narrowly enough, nor with enough articulatory precision, to create turbulent airflow. Therefore, approximants fall between fricatives, which have a degree of constriction tight enough to produce a turbulent airstream, and vowels, which have no constriction. This class includes vowel-like sounds such as [j] and [w] (as in yes and west, respectively), as well as liquids such as [l] and [ɹ] (as in less and rest, respectively), among other consonants with relatively low degrees of stricture. They are a subclass of sonorants and continuants. TerminologyBefore Peter Ladefoged coined the term approximant in the 1960s, the terms frictionless continuant and semivowel were used to refer to non-lateral approximants. As a distinctive feature, approximant has also sometimes been expanded to encompass vowels in addition to semivowels (glides) and liquids. SemivowelsSome approximants resemble vowels in acoustic and articulatory properties and the terms semivowel and glide are often used for these non-syllabic vowel-like segments. The correlation between semivowels and vowels is strong