Laminal consonant in the context of "Extensions to the IPA"

The Extensions to the International Phonetic Alphabet for Disordered Speech, commonly abbreviated extIPA /ɛkˈstaɪpə/, are a set of letters and diacritics devised by the 1989 Kiel Convention and later by the International Clinical Phonetics and Linguistics Association (ICPLA) to augment the International Phonetic Alphabet for the phonetic transcription of disordered speech. Some of its symbols are also used to represent features of normal speech in IPA transcriptions, and are accepted for that purpose by the International Phonetic Association.

Many sounds found only in disordered speech are indicated with diacritics, though an increasing number of dedicated letters are used as well. Special letters are included to transcribe the speech of people with lisps and cleft palates. The extIPA repeats several traditional IPA diacritics that the ICPLA has found are unfamiliar to most speech pathologists but which transcribe features that are common in disordered speech. These include preaspiration ⟨ʰ◌⟩, linguolabials ⟨◌̼⟩, laminal fricatives [s̻, z̻], and ⟨*⟩ for a sound (segment or feature) that has no available symbol (letter or diacritic). The novel transcription ⟨ɹ̈⟩ is used for an English molar-r, as opposed to ⟨ɹ̺⟩ for an apical r; these articulations are acoustically indistinguishable and so are rarely identified in non-disordered speech.

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.

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.

Thorn or þorn (Þ, þ) is a letter in the Old English, Old Norse, Old Swedish and modern Icelandic alphabets, as well as modern transliterations of the Gothic alphabet, Middle Scots, and some dialects of Middle English. It was also used in medieval Scandinavia but was later replaced with the digraph th, except in Iceland, where it survives. The letter originated from the rune ᚦ (Thurisaz) in the Elder Futhark and was called thorn in the Anglo-Saxon and thorn or thurs in the Scandinavian rune poems. It is similar in appearance to the archaic Greek letter sho (ϸ), although the two are historically unrelated. The only language in which þ is currently in use is Icelandic.

It represented a voiceless dental fricative [θ] or its voiced counterpart [ð]. However, in modern Icelandic it represents a laminal voiceless alveolar non-sibilant fricative [θ̠], similar to th as in the English word thick, or a (usually apical) voiced alveolar non-sibilant fricative [ð̠], similar to th as in the English word the. Modern Icelandic usage generally excludes the latter, which is instead represented with the letter eth ⟨Ð, ð⟩; however, [ð̠] may occur as an allophone of /θ̠/, and written ⟨þ⟩, when it appears in an unstressed pronoun or adverb after a voiced sound.