Consonants

Consonants are a class of speech sounds produced with constriction or closure in the vocal tract, in contrast to vowels, which are produced with a relatively open vocal tract. In most writing systems they are represented by letters that denote these sounds. The inventory of consonants and their distribution varies between languages, so classifications are often language-specific. Consonants can be distinguished by features such as voicing (voiced vs. voiceless) and by how the airstream is modified during articulation.

Consonants are commonly classified by place of articulation — bilabial, labiodental, dental or interdental, alveolar, postalveolar, palatal, velar, uvular, and glottal — and by manner of articulation — stops/plosives, nasals, trill and tap/flap, fricatives, affricates, approximants, and lateral sounds. Additional distinctions include aspiration (a puff of air after voiceless stops) and phonation type. Some languages use phonation contrasts or rare articulations such as ejectives or implosives. Orthography does not always map one-to-one to phonemes; a single letter can represent multiple sounds or a single sound can be written with several letters.

Consonants interact with syllable structure: many languages allow onset clusters (several consonants beginning a syllable) and/or coda clusters (consonants ending a syllable), while others restrict clusters. Examples of common consonant sounds include p, b, t, d, k, g; m, n, ŋ; f, v, s, z; ʃ, ʒ; t͡ʃ, d͡ʒ; l, r; j, w. IPA is frequently used in phonetic descriptions to capture the precise articulation of sounds.