Sonants

Sonants, or sonorants, are a class of speech sounds produced with relatively free airflow and often with vocal fold vibration. They tend to have oral resonances that give them a distinct, vowel-like quality. In many analyses, vowels are included in the broader category of sonorants, alongside several consonant types.

The core members of the sonorant group are vowels, nasals (such as m, n, ŋ), liquids (such as l and r), and approximants (such as w and j). Some phonologies also recognize syllabic consonants, like a syllabic l or n, which function as the nucleus of a syllable in certain contexts. These sounds are typically easier to sustain and contain clearer formant structures than obstruents.

Sonorants are contrasted with obstruents, which include stops, fricatives, and affricates. Obstruents involve a constricted vocal tract and audible turbulence or stops in the airstream, whereas sonorants involve less obstruction and more continuous voicing or periodic vibration. As a result, sonorants generally have lower spectral noise and a stronger, more periodic acoustic signature.

In phonology, sonorants often play a central role in syllable structure, frequently serving as syllable nuclei in addition to vowels or as allowable consonantal syllables in certain languages. They also participate in processes such as assimilation and syllabification in ways that differ from obstruents.

Overall, the term sonorant provides a production- and acoustics-based grouping that helps distinguish a family of sounds with relatively open articulation and resonant, vowel-like qualities.