Sonorant

Definition:

A sonorant is a speech sound produced with a vocal tract configuration that allows continuous, relatively unimpeded airflow, resulting in a voiced, resonant sound. Sonorant consonants include nasals (/m, n, ŋ/), liquids (/l, r/), and glides (/w, j/). All vowels are also sonorants. Sonorants contrast with obstruents, which significantly obstruct airflow.


In-Depth Explanation

The sonorant–obstruent distinction is fundamental to phonological theory and affects phonological processes across languages. Key properties of sonorants:

  • Voiced by default. Sonorants are inherently voiced in most languages because the open vocal tract configuration naturally facilitates vocal fold vibration. Voiceless sonorants exist (like the voiceless /l/ in Welsh ll) but are cross-linguistically rare.
  • Higher sonority. On the sonority hierarchy, sonorants rank above obstruents. This explains syllable structure patterns: sonorants tend to be closer to the syllable nucleus (the vowel) while obstruents sit at syllable edges.
  • They carry tone and pitch. In tonal and pitch-accent languages like Japanese, pitch distinctions are realized on sonorants (including vowels) because they have regular voicing. Obstruents can disrupt or reset pitch patterns.
TypeExamples (English)Examples (Japanese)Properties
Nasal/m, n, ŋ//m, n, ɴ/Complete oral closure but airflow through nose
Liquid/l, r//ɾ/ (flap)Partial obstruction, lateral or central
Glide/w, j//w, j/Very slight constriction, vowel-like
Vowel/a, e, i, o, u//a, e, i, o, ɯ/No obstruction, maximum sonority

In Japanese phonology, sonorants play several distinctive roles:

  • Moraic nasals: The moraic nasal /ɴ/ (ん) is a sonorant that occupies its own mora. It assimilates to the place of articulation of the following consonant: [m] before /b, p/, [n] before /t, d/, [ŋ] before /k, g/.
  • The Japanese /r/: Japanese has a single liquid phoneme — a flap /ɾ/ — rather than the /l/ vs. /r/ contrast in English. This is a major perception challenge for Japanese learners of English and English learners of Japanese alike.
  • Pitch accent: Japanese pitch accent patterns are realized primarily on sonorants. High and low pitch distinctions are clearly audible on vowels and nasals.

Related Terms


See Also


Research

  • Ladefoged, P., & Johnson, K. (2014). A Course in Phonetics (7th ed.). Cengage Learning. — Comprehensive coverage of the sonorant class with articulatory descriptions and acoustic properties.
  • Vance, T. J. (2008). The Sounds of Japanese. Cambridge University Press. — Detailed analysis of Japanese sonorants including the moraic nasal and the flap /ɾ/.