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 ⟨z⟩, and the equivalent X-SAMPA symbol is . The IPA letter $⟨z⟩$ is not normally used for dental or postalveolar sibilants in narrow transcription unless modified by a diacritic (⟨z̪⟩ and ⟨z̠⟩ respectively).
 * The IPA symbol for the alveolar non-sibilant fricative is derived by means of diacritics; it can be ⟨ð̠⟩ or ⟨ɹ̝⟩.

Voiced alveolar sibilant
The voiced alveolar sibilant is common across European languages, but is relatively uncommon cross-linguistically compared to the voiceless variant. Only about 28% of the world's languages contain a voiced dental or alveolar sibilant. Moreover, 85% of the languages with some form of are languages of Europe, Africa, or Western Asia.

Features

 * There are at least three specific variants of :
 * Dentalized laminal alveolar (commonly called "dental"), which means it is articulated with the tongue blade very close to the upper front teeth, with the tongue tip resting behind lower front teeth. The hissing effect in this variety of is very strong.
 * Non-retracted alveolar, which means it is articulated with either the tip or the blade of the tongue at the alveolar ridge, termed respectively apical and laminal. According to about half of English speakers use a non-retracted apical articulation.
 * Retracted alveolar, which means it is articulated with either the tip or the blade of the tongue slightly behind the alveolar ridge, termed respectively apical and laminal. Acoustically, it is close to or laminal.

Voiced alveolar non-sibilant fricative
The voiced alveolar non-sibilant fricative  is a consonantal sound. As the International Phonetic Alphabet does not have separate symbols for the alveolar consonants (the same symbol is used for all coronal places of articulation that are not palatalized), it can represent the sound as in a number of ways including ⟨ð̠⟩ or ⟨ð͇⟩ (retracted or alveolarized, respectively), ⟨ɹ̝⟩ (constricted ), or ⟨d̞⟩ (lowered ).

Few languages also have the voiced alveolar tapped fricative, which is simply a very brief apical alveolar non-sibilant fricative, with the tongue making the gesture for a tapped stop but not making full contact. It can be indicated in the IPA with the lowering diacritic to show that full occlusion does not occur. Flapped fricatives are theoretically possible but are not attested.

Features
However, it does not have the grooved tongue and directed airflow, or the high frequencies, of a sibilant.

Voiced lateral-median fricative
The voiced alveolar non-sibilant fricative (also known as a "lisp" fricative) is a consonantal sound. Consonants is pronounced with simultaneous lateral and central airflow.

Features
However, it does not have the grooved tongue and directed airflow, or the high frequencies, of a sibilant.