Alveolar ridge in the context of "Voiceless alveolar fricative"

A voiceless alveolar affricate is a type of affricate consonant pronounced with the tip or blade of the tongue against the alveolar ridge (gum line) just behind the teeth. There are several types with significant perceptual differences:

• The voiceless alveolar sibilant affricate [t͡s] is the most common type, similar to the ts in English cats.
• The voiceless alveolar non-sibilant affricate [t͡θ̠] or [t͡θ͇], using the alveolar diacritic from the Extended IPA, is somewhat similar to the th in some pronunciations of English eighth. It is found as a regional realization of the sequence /tr/ in some Sicilian dialects of Standard Italian.
• The voiceless alveolar lateral affricate [t͡ɬ] is found in certain languages, such as Cherokee, Mexican Spanish, and Nahuatl.
• The voiceless alveolar retracted sibilant affricate [t͡s̺], also called apico-alveolar or grave, has a weak hushing sound reminiscent of retroflex affricates. One language in which it is found is Basque, where it contrasts with a more conventional non-retracted laminal alveolar affricate.

A retroflex (/ˈrɛtrəflɛks, -roʊ-/ ) or cacuminal (/kəˈkjuːmɪnəl/ ) consonant is a coronal consonant where the tongue has a flat, concave, or even curled shape, and is articulated between the alveolar ridge and the hard palate. They are sometimes referred to as cerebral consonants—especially in Indology.

The Latin-derived word retroflex means "bent back"; some retroflex consonants are pronounced with the tongue fully curled back so that articulation involves the underside of the tongue tip (subapical). These sounds are sometimes described as "true" retroflex consonants. However, retroflexes are commonly taken to include other consonants having a similar place of articulation without such extreme curling of the tongue; these may be articulated with the tongue tip (apical) or the tongue blade (laminal). When apical, they have been called apico-domal consonants.

A voiced alveolar affricate is a type of affricate consonant pronounced with the tip or blade of the tongue against the alveolar ridge (gum line) just behind the teeth. There are several types with significant perceptual differences:

• The voiced alveolar sibilant affricate [d͡z] is the most common type, similar to the ds in English lads.
• The voiced alveolar non-sibilant affricate [dð̠], or [dð͇] using the alveolar diacritic from the Extended IPA, is found, for example, in some dialects of English and Italian.
• The voiced alveolar retracted sibilant affricate [d͡z̺]

Alveolar consonants (/ælˈviːələr/ ; UK also /ælviˈoʊlər/) are articulated with the tongue against or close to the superior alveolar ridge, which is called that because it contains the alveoli (the sockets) of the upper teeth. Alveolar consonants may be articulated with the tip of the tongue (the apical consonants), as in English, or with the flat of the tongue just above the tip (the "blade" of the tongue; called laminal consonants), as in French and Spanish.

The International Phonetic Alphabet (IPA) does not have separate symbols for the alveolar consonants. Rather, the same symbol is used for all coronal places of articulation that are not palatalized like English palato-alveolar sh, or retroflex. To disambiguate, the bridge ([s̪, t̪, n̪, l̪], etc.) may be used for a dental consonant, or the under-bar ([s̠, t̠, n̠, l̠], etc.) may be used for the postalveolars. [s̪] differs from dental [θ] in that the former is a sibilant and the latter is not. [s̠] differs from postalveolar [ʃ] in being unpalatalized.

Postalveolar (post-alveolar) consonants are consonants articulated with the tongue near or touching the back of the alveolar ridge. Articulation is farther back in the mouth than the alveolar consonants, which are at the ridge itself, but not as far back as the hard palate, the place of articulation for palatal consonants. Examples of postalveolar consonants are the English palato-alveolar consonants [ʃ] [tʃ] [ʒ] [dʒ], as in the words "ship", "'chill", "vision", and "jump", respectively.

There are many types of postalveolar sounds—especially among the sibilants. The three primary types are palato-alveolar (such as [ʃ ʒ], weakly palatalized; also alveopalatal), alveolo-palatal (such as [ɕ ʑ], strongly palatalized), and retroflex (such as [ʂ ʐ], unpalatalized). The palato-alveolar and alveolo-palatal subtypes are commonly counted as "palatals" in phonology since they rarely contrast with true palatal consonants.