Voice (phonetics)
| Voiced | |
|---|---|
| ◌̬ | |
| |
| Voiceless | |
|---|---|
| ◌̥ |
| Phonation |
|---|
| Glottal states |
| From open to closed: |
| Voicelessness (full airstream) |
| Breathy voice (murmur) |
| 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) |
| Non-phonemic phonation |
| Whisper |
| Falsetto |
Voice or voicing is a term used in phonetics and phonology to characterize speech sounds, with sounds described as either voiceless (unvoiced) or voiced. The term, however, is used to refer to two separate concepts. Voicing can refer to the articulatory process in which the vocal cords vibrate. This is its primary use in phonetics to describe phones, which are particular speech sounds. It can also refer to a classification of speech sounds that tend to be associated with vocal cord vibration but need not actually be voiced at the articulatory level. This is the term's primary use in phonology when describing phonemes, or in phonetics when describing phones.
At the articulatory level, 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 the pairs of sounds that are associated with the English letters "s" and "z". The two sounds are symbolically written [s] and [z] to distinguish them from the English letters, which have several possible pronunciations depending on context. If one places the fingers on the voice box (i.e. 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 most European languages, with a notable exception being Icelandic, vowels and other sonorants (consonants such as m, n, l, and r) are modally voiced.
When used to classify speech sounds, voiced and unvoiced are merely labels used to group phones and phonemes together for the purposes of classification. We return to this below.
Notation
The International Phonetic Alphabet has distinct letters for many voiceless and voiced pairs of consonants (the obstruents), such as [p b], [t d], [k ɡ], [q ɢ]. In addition, there is a diacritic for voicedness, [ ̬ ] (U+032C ̬ combining caron below). Diacritics are typically used with letters for prototypically voiceless sounds.
English examples
The distinction between the articulatory use of voice and the phonological use rests on the distinction between phone and phoneme. The difference is best illustrated by a rough example. Words are composed of phonemes. The English word "pods" is made up of a sequence of phonemes, represented symbolically as /pɒdz/, or the sequence of /p/, /ɒ/, /d/, and /z/. Each letter is an abstract symbol for a phoneme. This is a part of our grammatical knowledge.
Consonant phonemes are classified as either voiced or voiceless. Some voiced phonemes of English are /b, d, ɡ, v, z/. Each of these obstruents has an unvoiced counterpart, /p, t, k, f, s/. The classification is useful for describing phonological processes such as vowel lengthening that occurs before voiced consonants but not before unvoiced consonants or vowel quality changes (i.e. the sound of the vowel) in some dialects of English that occur before unvoiced but not voiced consonants.
However, phonemes are not sounds. Rather, phonemes are, in turn, converted to phones before being spoken. The /z/ phoneme, for instance, can actually be pronounced as the [s] phone or the [z] phone because /z/ is frequently devoiced in fluent speech, especially at the end of an utterance. And so the sequence of phones for "pods" might be [pɒds] or [pɒdz]. The different type of brackets indicates that these are symbols for phones now. As described above, while the [z] phone has articulatory voicing, the [s] phone does not.
English has four pairs of fricative phones which can be divided into a table by place of articulation and voicing. The voiced fricatives can readily be felt to have voicing throughout the duration of the phone.
Degrees of voicing
| Voice onset time |
|---|
| + Aspirated |
| 0 Tenuis |
| − Voiced |
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 the latter.
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.
See also
References
- Ladefoged, Peter; Maddieson, Ian (1996). The Sounds of the World's Languages. Oxford: Blackwell. ISBN 0-631-19814-8.
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