Voiced alveolar fricative

The voiced alveolar fricatives are consonantal sounds. The symbol in the International Phonetic Alphabet that represents these sounds depends on whether a sibilant or non-sibilant fricative is being described.
*The symbol for the alveolar sibilant is , and the equivalent X-SAMPA symbol is z. The IPA symbol [z] is not normally used for dental or postalveolar sibilants unless modified by a diacritic ( and respectively).
*The IPA symbol for the alveolar non-sibilant fricative is derived by means of diacritics; it can be or .

coronal fricatives	dental	alveolar	postalveolar
sibilant	|
non-sibilant	|

The voiced alveolar sibilant

Features

Features of the voiced alveolar fricative:
* Its manner of articulation is sibilant fricative, which means it is produced by directing air flow through a groove in the tongue at the place of articulation and directing it over the sharp edge of the teeth, causing high-frequency turbulence.
* Its place of articulation is alveolar, which means it is articulated with either the tip or the blade of the tongue against the alveolar ridge, termed respectively apical and laminal.
* Its phonation type is voiced, which means the vocal cords are vibrating during the articulation.
* It is an oral consonant, which means air is allowed to escape through the mouth.
* It is a central consonant, which means it is produced by allowing the airstream to flow over the middle of the tongue, rather than the sides.
* The airstream mechanism is pulmonic egressive, which means it is articulated by pushing air out of the lungs and through the vocal tract, rather than from the glottis or the mouth.

In English

The voiced alveolar fricative occurs in English, and it is the sound denoted by the letter 'z' in zoo or the letter 's' in roses.

The voiced alveolar non-sibilant fricative

Features

The features of the voiceless alveolar non-sibilant fricative are identical to those above, except that,
* Its manner of articulation is simple fricative, which means it is produced by constricting air flow through a narrow channel at the place of articulation, causing turbulence, but without the grooved tongue and directed airflow, or the high frequencies, of a sibilant.

Found in

;EnglishIn some urban South African dialects of English, is pronounced , while in Scouse, can sometimes have either this sound or a corresponding affricate. (Marotta and Barth 2005)

;IcelandicThe Icelandic letter ð (eth) is used for this sound. (It is replaced by þ (thorn) at the beginning of a word, where it is a voiceless alveolar non-sibilant fricative. Old English had a similar allophonic distribution but used the letters þ and ð indiscrimately for both the voiceless and voiced dental fricative; in modern English both are replaced by the digraph "th".) Icelandic is usually apical, whereas is laminal.
*Icelandic þakið "roof".

See also

* List of phonetics topics

References

* Marotta, G. and Barth, M., Acoustic and sociolingustic aspects of lenition in Liverpool English, Studi Linguistici e Filologici Online 3.2, pp377-413. Available online (including sound files).