- See also consonance in music.
A consonant is a sound in spoken language that is characterized by a constriction or closure at one or more points along the vocal tract. The word consonant comes from Latin meaning "sounding with" or "sounding together", the idea being that consonants don't sound on their own, but only occur with a nearby vowel, which is the case in Latin. This conception of consonants, however, does not reflect the modern linguistic understanding which defines consonants in terms of vocal tract constrictions.
There are a group of consonants called sonorants that sometimes act as vowels, occupying the peak of a syllable, and sometimes act as consonants. For example, in English, the sound [m] in "mud" is a consonant, but in "prism", it occupies an entire syllable, as a vowel would.
The word consonant is also used to refer to letters of an alphabet that denote a consonant sound. Consonant letters in the English alphabet are B, C, D, F, G, H, J, K, L, M, N, P, Q, R, S, T, V, W, X, Z, and sometimes Y — the letter Y stands for the consonant [j] in "yoke" but for the vowel in "myth", for example.
Since the number of consonants in the world's languages is much greater than the number of consonant letters in most alphabets, linguists have devised systems such as the International Phonetic Alphabet (IPA) to assign a unique symbol to each possible consonant. In fact, the Latin alphabet, which is used to write English, has fewer consonant letters than English has consonant sounds, so some letters represent more than one consonant, and digraphs like "sh" and "th" are used to represent some sounds. Many speakers aren't even aware that the "th" sound in "this" is a different sound from the "th" sound in "thing" (in IPA they're [ð] and [θ], respectively).
Each consonant can be distinguished by several features:
- The manner of articulation is the method that the consonant is articulated, such as nasal, stop, or approximant.
- The place of articulation is where in the vocal tract the articulators of the consonant act, such as bilabial, alveolar, or velar. Additionally, there may be a simultaneous narrowing at another place of articulation, e.g. a palatalisation or a pharyngealisation.
- The phonation method of a consonant is whether or not the vocal cords are vibrating during articulation of a consonant. When the vocal cords are vibrating, the consonant is voiced; when they're not, it's voiceless. Aspiration is also a feature of phonation.
- The airstream mechanism is how the air moves through the vocal tract during articulation. Most languages have exclusively pulmonic egressive consonants, but ejectives, clicks, and implosives use different mechanisms.
- The length is how long the articulation of a consonant takes. This feature is not distinctive in English, but various languages such as Italian, Japanese and Finnish have two lenght levels, "short consonants" and "geminates". Estonian and some Sami languages have three lenght levels: "short", "geminate" and "over-long".
- The articulatory force is how much muscular energy is involved. This is disputed.
All English consonants can be classified by a combination of these, such as "voiceless alveolar stop consonant" [t]. In this case, the airstream mechanism is omitted.
Some pairs of consonants like p::b, t::d are sometimes called fortis and lenis.
The following tables list all the consonants listed by the IPA. The first table contains consonants articulated in the front part of the mouth, and the second table contains consonants articulated in the back part of the mouth. The places of articulation are listed on top, and the manners of articulation on the left side. Where consonants occur in pairs, the consonant on the left represents a voiceless articulation and the consonant on the right represents a voiced articulation.