The Extensions to the International Phonetic Alphabet for Disordered Speech, commonly abbreviated extIPA , 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 , linguolabials , laminal fricatives , and for a sound (segment or feature) that has no available symbol (letter or diacritic). The novel transcription is used for an English molar-r, as opposed to for an apical r; these articulations are acoustically indistinguishable and so are rarely identified in non-disordered speech.
Sounds restricted to disordered speech include velopharyngeals, nasal fricatives (a.k.a. nareal fricatives) and some of the percussive consonants. Sounds sometimes found in the world's languages that do not have symbols in the basic IPA include denasals, the sublaminal percussive, palatal and velar lateral fricatives, and fricatives that are simultaneously lateral and sibilant.
There are two basic approaches to transcription in extIPA. One is to transcribe speech phonetically, without considering what the intended sounds are. For example, if a target sound is denasalized to , it is written . The other approach is to transcribe the target sound with diacritics to indicate how it is mispronounced. With this approach, denasalized is written , with the denasalization diacritic . This semi-phonemic approach is very common in the literature, but the ICPLA tries to discourage it. For this reason, in 2025 they specified the denasalization diacritic as meaning partially denasalized.
The extIPA was substantially revised and expanded in 2015; the new symbols were added to Unicode in 2021. Two diacritics were changed in 2024 to reduce ambiguity. (See .)
Letters The non-IPA letters found in the extIPA are listed in the following table. VoQS letters may also be used, as in for a buccal interdental trill (a raspberry), as VoQS started off as a subset of extIPA.Ball et al. (2018)
Several letters and superscript forms were added to Unicode 14 and 15. They are included in the free Gentium and Andika fonts.
CategoryLetterSuperscript and exampleUnicodeDescriptionLateral U+02AA, U+10799Voiceless grooved lateral alveolar fricative, (a laterally lisped , with simultaneous airflow through the sibilant groove in the tongue and across the side of the tongue), intended for a lateral lisp U+02AB, U+1079AVoiced grooved lateral alveolar fricative, (a laterally lisped ) U+A78E, U+1079DVoiceless retroflex lateral fricative, implicit in standard IPA. U+1DF05, U+1079F Voiced retroflex lateral fricative, implicit in standard IPA. U+1DF06, U+107A1Voiceless palatal lateral fricative. The voiced fricative may be or, in standard IPA, . U+1DF04, U+1079CVoiceless velar lateral fricative. The voiced fricative may be or, in standard IPA, .Velopharyngeal U+02A9, U+10790Voiceless velopharyngeal fricative (often occurs with a cleft palate). The voiced fricative is . U+1DF00, (U+10790+107AA)Voiceless velopharyngeal trill or 'snort'. (Velopharyngeal fricative accompanied by uvular trill. may be equivalent to .)Velodorsal – U+1DF03Voiceless velodorsal plosive. (The old IPA letter for a velar click, , was provided for a voiceless velodorsal plosive from 2008 to 2015.) – U+1DF01Voiced velodorsal plosive – U+1DF07Velodorsal nasalPharyngeal – U+A7AF Voiceless upper-pharyngeal plosive – U+1DF02 Voiced upper-pharyngeal plosive Percussive ( ) U+02ACBilabial percussive (for lips smacking together; cf. non-percussive for lips smacking apart) ( ) U+02ADBidental percussive (gnashing teeth) U+00A1, U+A71ESublaminal lower-alveolar percussive (tongue slap). Used with letters for alveolar and palatal clicks to indicate clicks with percussive release, or "clucks", and .
Diacritics The extIPA has explicitly endorsed some rarer uses of regular IPA diacritics, such as for pre-aspiration, and has added some new ones, such as for uvularization. Some of these extIPA diacritics are occasionally used for non-disordered speech, for example for the unusual airstream mechanisms of Damin.
One extension of regular IPA is the use of parentheses around diacritics to indicate partial application of that diacritic: a pair of parentheses around a diacritic indicates that the diacritic only partially applies (in degree or duration), while a single parenthesis at the left or right of the diacritic indicates that the segment is partially affected at its beginning or end. These conventions may be convenient for representing various voice onset times. Phonation diacritics may also be prefixed or suffixed to represent relative timing beyond the segment (pre- and post-voicing etc.). The following are examples; in principle, any IPA or extIPA diacritic may be parenthesized or displaced in this manner.
Partial application of diacritics (examples) partial/central voicing of partial/central devoicing of subscript: U+1ABD; superscript: 1ABB initial voicing initial devoicing subscript: U+1AC3; superscript: 1AC1 final voicing final devoicing subscript: U+1AC4; superscript: 1AC2 partial murmuring of partial nasalization of Displaced timing (examples) pre-voiced post-voiced U+02EC with a creaky offglide with extended voicelessness U+02F7 (˷), U+02F3 (˳)
The transcriptions for partial voicing and devoicing may be used in either the sense of degrees of voicing or in the sense that the voicing is discontinuous. For the former, both parentheses indicate the sound is mildly (partially) voiced throughout, and single parentheses mean a partial degree of voicing at the beginning or end of the sound. For the latter, both parentheses mean the sound is (de)voiced in the middle, while the single parentheses mean complete (de)voicing at the beginning or end of the sound. The implication is that such voicing or devoicing is atypical of the language being spoken. For example, would be used for the usual devoicing or partial devoicing of the language, while would indicate that the transcriber found the devoicing to be atypical, as in pathological speech. Similarly, would indicate atypical devoicing at the beginning of the segment. However, some authors use the parentheses for typical devoicing in close transcription. For example, the Bardi word aamba 'man', with the usual initial and final devoicing of that language, has been transcribed .Claire Bowern (2012) A Grammar of Bardi, p. 83
Altering the position of a diacritic relative to the letter indicates that the phonation begins before the consonant or vowel does or continues beyond it. The voiceless ring and other phonation diacritics can be used in the same way if needed. For example, indicates that voicelessness continues past the , more or less equivalent to .
Other extIPA diacritics are:
Airstream mechanism U+2193 (after a letter) ingressive airstream U+2191 (after a letter) egressive airstream (in isolation) inhalation (in isolation) exhalationPhonation U+02ED unaspirated U+02B0 pre-aspirationNasalization U+033E (on a nasal letter) nareal fricative U+10790 velopharyngeal frication (especially noisy nasal airstream caused by turbulent airflow through the velopharyngeal port) (on an oral letter) nasal fricative escape (audible turbulent airflow through the nostrils, as with a nasal lisp) U+034A partially denasalized (as with a headcold; complements the nasal diacritic)Articulatory strength U+0348 strong articulation (not necessarily fortis); may be used for a true glottal fricative U+0349 weak articulation (not necessarily lenis)Articulation U+0346 (on a labial letter) dentolabial U+0346 +032A (on a coronal letter) interdental (on a coronal letter) class-3 occlusion (tongue protrudes past upper teeth, as with a severe underbite) (on a glottal letter) bidental U+0347 (on a coronal letter) alveolar U+034D labial spreading (on a labial letter) labioalveolar (class-2 occlusion, as with a severe overbite) (complements the diacritics for rounding – see rounded vowel) U+034E whistled U+033B laminal fricatives (including lowered tongue tip) , (as IPA) bunched-r (molar-r) and apical-r, respectively , U+0355,U+0354 offset to the left and right, respectivelyTiming U+0362 slurred/sliding articulation (a consonantal diphthong, moving from one articulation to another within the time of a single segment) U+005C stutter (reiterated articulation)
Diacritics may be placed within parentheses as the voicing diacritics are above. For example, indicates a partially denasalized .
The arrow for sliding articulation was first used for for 'watch' and for 'zipper'. It is most commonly observed in quick changes from the blade to the tip of the tongue (laminal to apical) in plosives and fricatives, such as and , or vice versa, but is not limited to that; the consonants may also be labial or dorsal, e.g. and .Bernhardt & Ball (1993) Characteristics of Atypical Speech currently not included in the Extensions to the IPA. JIPA 23:1, p. 35–36.
The slit-grooved distinction of the channel shape of front fricatives may be handled with these diacritics, with for example for grooved (sibilant) dental fricatives, and for ungrooved (non-sibilant) alveolar fricatives. This is a common topic in speech pathology, though occur in non-pathological speech in some languages.
Any IPA letter may be used in superscript form as a diacritic, to indicate the onset, release or 'flavor' of another letter. In extIPA, this is provided specifically for the fricative release of a plosive. For example, is with a lateral-fricative release (similar to the velar lateral affricate , but with less frication); is with lateral-plus-central release. Combining diacritics can be added to superscript diacritics, such as for with bidental aspiration.
The VoQS (voice-quality symbols) take IPA and extIPA diacritics, as well as several additional diacritics that are potentially available for extIPA transcription. The subscript dot for 'whisper' is sometimes found in IPA transcription, though in IPA the diacritic has also been used for apical-retroflex articulation.
Prosodic notation and indeterminate sounds The Extended IPA has adopted bracket notation from conventions transcribing discourse. Parentheses are used to indicate mouthing (silent articulation), as in the common silent sign to hush . Parentheses are also used to indicate silent pauses, for example (...); the length of the pause may be indicated, as in (2.3 sec). A very short (.) may be used to indicate an absence of co-articulation between adjacent segments, for instance rather than .
Double parentheses indicate that transcription is uncertain because of extraneous noise or speech, as when one person talks over another. As much detail as possible may be included, as in ⸨2 syll.⸩ or ⸨2σ⸩ for two obscured syllables. This is also IPA usage. Sometimes the obscuring noise will be indicated instead, as in ⸨cough⸩ or ⸨knock⸩, as in the illustrative transcription below; this notation may be used for extraneous noise that does not obscure speech, but which the transcriber nonetheless wishes to notate (e.g. because someone says 'excuse me' after coughing, or verbally responds to the knock on the door, and the noise is thus required to understand the speech).