Sonorants

Sonorants are a class of speech sounds produced with relatively open configurations of the vocal tract, allowing air to flow with little turbulent constriction. In most languages, they are voiced and form a key contrast to obstruents, such as stops, fricatives, and affricates, which involve more constricted airflow or noise. The set typically includes vowels and several consonant types that function as resonant, syllabic, or nucleus-like elements in syllables.

The main subtypes are vowels; glides (semivowels); liquids; and nasals. Vowels are the open, voiced nuclei of syllables. Glides, such as [j] and [w], are semi-vowels that glide toward neighboring vowels. Liquids, including the lateral [l] and the rhotic [r], are consonants with relatively open constriction. Nasals, such as [m], [n], and [ŋ], involve air flowing through the nasal cavity while the oral tract is closed at the place of articulation.

Acoustically, sonorants tend to have clear, periodic voicing and, with the exception of nasals and some liquids, exhibit robust formant structure. Nasals show a nasal resonance that dampens high-frequency energy, giving them a distinct spectral profile compared to vowels and other consonants.

In syllable structure, sonorants frequently serve as syllabic elements or as the core of syllables, and they readily form onsets with other consonants. The Sonority Sequencing Principle describes a general tendency for syllables to rise in sonority toward the nucleus (often a vowel) and fall toward the coda.

Cross-linguistically, the exact inventory of sonorants and their phonation can vary. In many languages, the set is voiced across the board, though phonological processes can produce voiceless or partially devoiced realizations in certain environments. The concept of sonorants is widely used to analyze syllable structure and phonotactics.