Voice (phonetics)
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| Phonation |
|---|
| Glottal states (from open to closed) |
| voiceless (full airstream) |
| breathy voice (murmur) |
| whisper |
| slack voice |
| modal voice (maximum vibration) |
| stiff voice |
| creaky voice (restricted airstream) |
| glottalized (blocked airstream) |
| Supra-glottal phonation |
| faucalized voice ("hollow") |
| harsh voice ("pressed") |
| strident (harsh trilled) |
| Vocal registers |
| whistle |
| falsetto |
| modal |
| vocal fry |
In the phonetics of languages such as English, voice or voicing is one of the three major parameters used to describe a speech sound. It is usually treated as a binary parameter with sounds being described as either voiceless (unvoiced) or voiced, although in fact there are degrees of voicing.
A voiced sound is one in which the vocal cords vibrate, and a voiceless sound is one in which they do not. Voicing is the difference between pairs of sounds such as [s] and [z] in English. If one places the fingers on the voice box (ie the location of the Adam's apple in the upper throat), one can feel a vibration when one pronounces zzzz, but not when one pronounces ssss. (For a more detailed, technical explanation, see modal voice and phonation.)
In European languages such as English, vowels and other sonorants (consonants such as m, n, l, and r) are modally voiced. In most European languages, other consonants contrast between voiced and unvoiced sounds such as [s] and [z], though in English many of these are at least partially devoiced in most environments.
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[edit] English examples
English is described as a voicing contrast in a class of consonants called obstruents. In some of these, called fricatives, this truly is a simple voicing contrast. The buzz of the voice box can be felt with the sounds in the second column as described above:
| Articulation | Voiceless | Voiced |
|---|---|---|
| Pronounced with the lip against the teeth: | [f] (fan) | [v](van) |
| Pronounced with the tongue against the teeth: | [θ] (thin, thigh) | [ð] (then, thy) |
| Pronounced with the tongue near the gums: | [s] (sip) | [z] (zip) |
| Pronounced with the tongue bunched up: | [ʃ] (pressure) | [ʒ] (pleasure) |
However, in a class of consonants called plosives, the contrast is one of when voicing starts for the following vowel. In some, traditionally said to be "voiceless", there is a delay, with a puff of air between the consonant and a following vowel. These consonants are said to be aspirated, and the puff of air can be felt (for example by saying pan and ban into the palm of the hand) or observed in the flicker of a candle flame held near the mouth. In others, traditionally said to be "voiced", the onset of voicing is earlier, and may occur part-way through the pronunciation of the consonant. These consonants are best described as partially voiced.
| Articulation | Aspirated | Partially voiced |
|---|---|---|
| Pronounced with the lip against the teeth: | [p] (pin) | [b] (bin) |
| Pronounced with the tongue near the gums: | [t] (ten) | [d] (den) |
| Pronounced with the back of the tongue against the palate: | [k] (con) | [g] (gone) |
The principle auditory difference between the two, when they precede a vowel, is that puff of air. (There generally is no such aspiration after an s, so that the p in "spy" has more in common with the b of "buy" than with the p of "pie".) When these consonants follow a vowel, however, such as at the end of a word, in many English dialects there is often little or no aspiration. Instead, the principle auditory cue is the length of the preceding vowel, which is longer before "voiced" consonants. For many US and most Canadian speakers, this is especially apparent when the vowel is a long i, as in "write" vs. "ride". In fact, for many people the difference between "writer" and "rider" lies entirely in the vowel.
Finally, there is a class of consonants called affricates which combines the properties of plosive and fricative:
| Articulation | Aspirated | Partially voiced |
|---|---|---|
| Pronounced with the tongue bunched up: | [tʃ] (chin) | [dʒ] (gin) |
Other English sounds, the vowels, nasals, and liquids (called sonorants), are normally fully voiced. However, these consonants and unstressed vowels may be devoiced in certain positions, especially after aspirated consonants, as in police, tree, and play, where the voicing is delayed to the extent of missing the sonorant altogether.
[edit] Voiceless vowels and other sonorants
The IPA diacritic for devoicing is the under-ring, [ ̥]. This is used where no separate symbol is available, for example for devoicing vowels (vowels which have lost part of their sonority).
Vowels may be voiceless, usually allophonically. For example, the Japanese word sukiyaki is pronounced [su̥kijaki]. This may sound like [skijaki] to an English speaker, but the lips can be seen compressing for the [u̥]. Something very similar happens in English with words like peculiar and particular.
Types of consonants which are usually voiced (sonorants) may also be voiceless. Tibetan, for example, has a voiceless [l̥] in Lhasa, which sounds similar to, but is not as fricative as, the voiceless lateral fricative [ɬ]. Welsh has several voiceless sonorants: /m̥/, /n̥/, /ŋ̊/, and /r̥/, the latter in the name Rhiannon.
[edit] Voicing in English
Beside the pairs of voiceless and voiced 'obstruent' consonants given above, other voiced sounds in English are the nasals, i.e. /m, n, ŋ/; the approximants, i.e. /l, r, w, j/ (the last spelled <y>); and the vowels. These sounds are called sonorants.
In most languages, the difference between /b, d, g/ and /p, t, k/ is that /b, d, g/ are voiced, while /p, t, k/ are not. However, in many English dialects (including Received Pronunciation and American English), the main distinction is not that /b, d, g/ are voiced, but rather that /p, t, k/ are aspirated. That is, they differ in when voicing starts. In most English dialects, /b, d, g/ are partially voiceless in some environments, such as word initially. In fact, after an /s/, the contrast between /p, t, k/ and /b, d, g/ is lost; when a child learning English has acquired voicing distinctions, but not yet acquired the clusters /sp, st, sk/, the child's pronunciation of spy, sty, sky sounds to an adult like buy, die, guy.
[edit] Degrees of voicing
There are two variables to degrees of voicing: intensity (discussed under phonation), and duration (discussed under voice onset time). When a sound is described as "half voiced" or "partially voiced", it is not always clear whether that means that the voicing is weak (low intensity), or if the voicing only occurs during part of the sound (short duration). In the case of English, it is often the latter.
[edit] Voice and tenseness
There are languages with two sets of contrasting obstruents that are labelled /p t k f s x …/ vs. /b d ɡ v z ɣ …/ even though there is no involvement of voice (or voice onset time) in that contrast. This happens for instance in several Southern German dialects such as Alsatian or Swiss German. Since voice is not involved, this is explained as a contrast in tenseness, called a fortis and lenis contrast.
There is a hypothesis that the contrast between fortis and lenis consonants is related to the contrast between voiceless and voiced consonants, a relation based on sound perception as well as on sound production, where consonant voice, tenseness and length are but different manifestations of a common sound feature.
