Voiced labial–palatal approximant

A voiced labial–palatal (or labio-palatal) approximant is a type of consonantal sound, used in some spoken languages, for example, French huitième, read as [ɥitjɛm]. It has two constrictions in the vocal tract: with the tongue on the palate, and rounded at the lips. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɥ⟩, a rotated lowercase letter ⟨h⟩.

A labial–palatal approximant can in many cases be considered the semivocalic equivalent of the close front rounded vowel [y]. They alternate with each other in certain languages, such as French, and in the diphthongs of some languages, ⟨ɥ⟩ and ⟨y̑⟩ with the non-syllabic diacritic are used in different transcription systems to represent the same sound. Sometimes,^[1] ⟨y̆⟩ is written in place of ⟨y̑⟩, even though the former symbol denotes an extra-short [y] in the official IPA.

Some languages, though, have a palatal approximant that is unspecified for rounding, and therefore cannot be considered the semivocalic equivalent of either [y] or its unrounded counterpart [i]. An example of such a language is Spanish, in which a labialized palatal approximant (non-semivowel) appears allophonically with back vowels in words such as ayuda [aˈʝ̞ʷuð̞a] ('help'), while unrounded elsewhere, such as ayer [aˈʝ̞eɾ] ('yesterday'). Therefore, according to some sources, it is not correct to transcribe this sound with the symbol ⟨ɥ⟩, which has a different kind of rounding, or with a modified ⟨j⟩, which according to the same sources cannot be rounded at all; the only suitable transcription is ⟨ʝ̞ʷ⟩.^[2] See palatal approximant § Phonetic ambiguity and transcription usage for more information.

There is also a labialized post-palatal or pre-velar approximant^[3] in some languages, which is articulated slightly more back compared with the place of articulation of the prototypical labialized palatal approximant, though not as back as the prototypical labialized velar approximant. It can be considered the semivocalic equivalent of the close central rounded vowel [ʉ]. The International Phonetic Alphabet does not have a separate symbol for that sound, though it can be transcribed as ⟨ɥ᫢⟩ (a retracted ⟨ɥ⟩), ⟨ɥ̈⟩ (centralized ⟨ɥ⟩), ⟨w̟⟩ (advanced ⟨w⟩), or ⟨ẅ⟩ (centralized ⟨w⟩). These symbols may be used separately to distinguish compressed (exolabial) and protruded (endolabial) rounding, as in ⟨ɥ᫢⟩ vs ⟨w̟⟩ or ⟨ɥ̈⟩ vs ⟨ẅ⟩. Other possible transcriptions include ⟨ȷ̈ʷ⟩ (a centralized and labialized ⟨j⟩) and ⟨ʉ̯⟩ (a non-syllabic ⟨ʉ⟩). The para-IPA symbols ⟨ɥ w⟩ (barred ⟨ɥ w⟩) may also be used for the exolabial and endolabial variants of the post-palatal approximant respectively,^[4] and are scheduled to be supported by Unicode in September 2026.^[5]

Especially in broad transcription, a labialized post-palatal approximant may be transcribed as a palatalized and labialized velar approximant ⟨wʲ⟩.^{[citation needed]}