Editing Roundedness (section)

==Typology==
{{anchor|Protrusion|Compression|Protruded vowel|Compressed vowel}}
{{multiple image
|total_width=300
|header=Example 1
|image1=Vowel-narrow-protruded-1.png
|width1=714 |height1=680
|caption1=Protruded rounding
|image2=Vowel-narrow-compressed-1.png
|width2=792 |height2=826
|caption2=Compressed rounding
}}
{{multiple image
|total_width=300
|header=Example 2
|image1=Vowel-narrow-protruded-2.jpg
|width1=2048 |height1=1536
|caption1=Protruded rounding
|image2=Vowel-narrow-compressed-2.jpg
|width2=2048 |height2=1536
|caption2=Compressed rounding
}}
There are two types of vowel rounding: ''protrusion'' and ''compression''.<ref>Protrusion is also called ''endolabial'', ''lip-pouting'', ''horizontal lip-rounding'', ''outrounding'', or ''inner rounding'' {{harv|Trask|1996|p=180}}.</ref><ref>Compression is also called ''exolabial'', ''pursed'', ''vertical lip-rounding'', ''inrounding'', or ''outer rounding'' {{harv|Trask|1996|p=252}}.</ref><ref>[[Henry Sweet]] noted in 1890 that "the term 'inner rounding' derives from the use of the inner surfaces of the lips; the synonymous 'outrounding' derives from the forward projection of the lips. Both terms are justifiable, but their coexistence is likely to lead to serious confusion." {{harv|Trask|1996|p=180}}</ref> In protruded rounding, the corners of the mouth are drawn together and the lips protrude like a tube, with their inner surface visible. In compressed rounding, the corners of the mouth are drawn together, but the lips are also drawn together horizontally ("compressed") and do not protrude, with only their outer surface visible. That is, in protruded vowels the inner surfaces of the lips form the opening (thus the alternate term ''endolabial''), whereas in compressed vowels it is the margins of the lips which form the opening (thus ''exolabial).'' {{harvtxt|Catford|1982|p=172}} observes that back and central rounded vowels, such as German {{IPAslink|o}} and {{IPAslink|u}}, are typically protruded, whereas front rounded vowels such as German {{IPAslink|ø}} and {{IPAslink|y}} are typically compressed. Back or central compressed vowels and front protruded vowels are uncommon,<ref>{{harvtxt|Sweet|1877}} noted that they are less distinctive from unrounded vowels than their counterparts.</ref> and a contrast between the two types has been found to be phonemic in only one instance.<ref>[[Japanese language|Japanese]] has a back compressed {{IPAblink|ɯᵝ}} rather than protruded {{IPA|[u]}} {{harv|Okada|1999|p=118}}; [[Swedish language|Swedish]] also has a back compressed {{IPA|[ɯᵝ]}} {{angbr|o}} as well as both front compressed {{IPA|[y]}} {{angbr|u}} and front protruded {{IPA|[yʷ]}} {{angbr|y}} {{harv|Engstrand|1999|p=141}}; the front rounded vowels contrast in ''ruta'' 'window pane' and ''ryta'' 'roar' {{harv|Ladefoged|Maddieson|1996|p=292}}.</ref>

There are no dedicated IPA diacritics to represent the distinction, but the superscript IPA letter {{IPAalink|β|◌ᵝ}} or {{IPAalink|ʋ|◌ᶹ}} can be used for compression<ref>E.g. {{angbr IPA|ɨᵝ}} in {{harvtxt|Flemming|2002|p=83}}; the IPA ''Handbook'' recommends that {{angbr IPA|ᶹ}} "might be used" for "a secondary reduction of the lip opening accompanied by neither protrusion nor velar constriction".</ref> and {{angbr IPA|◌ʷ}} for protrusion. Compressed vowels may be pronounced either with the corners of the mouth drawn in, by some definitions rounded, or with the corners spread and, by the same definitions, unrounded. The distinction may be transcribed {{angbr IPA|{{IPAplink|ʉ}}ᵝ uᵝ}} vs {{angbr IPA|{{IPAplink|ɨ}}ᵝ ɯᵝ}} (or {{angbr IPA|ʉᶹ uᶹ}} vs {{angbr IPA|ɨᶹ ɯᶹ}}).<ref>Occasionally other symbols may be used, such as protruded {{angbr|ỿ}} ({{IPA|[yʷ]}}) and compressed {{angbr|ꝡ}} ({{IPA|[ɰᵝ]}}).{{Citation needed|date=December 2024|reason=Appears to be original research. What is the source for the use of these two letters to denote different types of rounding?}} To avoid the implication that the superscript represents an off-glide, it might be placed above the base letter: {{angbr IPA|y&#x1DF1;, ɯ&#x1DE9;}}. Ladefoged & Maddieson use old IPA {{angbr IPA|◌̫}} for protrusion (w-like labialization without velarization), while {{harvtxt|Kelly|Local|1989|p=154}} use w {{angbr IPA|◌ᪿ}} for protrusion (e.g. {{angbr IPA|øᪿ}}) and a reversed w {{angbr IPA|◌ᫀ}} for compression (e.g. {{angbr IPA|uᫀ}}). This recalls an old IPA convention of rounding an unrounded vowel letter like ''i'' with a subscript omega, and unrounding a rounded letter like ''u'' with a turned omega (Jespersen & Pedersen 1926: 19).</ref>

The distinction between protruded {{IPA|[u]}} and compressed {{IPA|[y]}} holds for the [[semivowel]]s {{IPA|[w]}} and {{IPA|[ɥ]}} as well as labialization. In [[Akan language|Akan]], for example, the {{IPAblink|ɥ}} is compressed, as are [[labio-palatalization|labio-palatalized]] consonants as in ''Twi'' {{IPA|[tɕᶣi̘]}} "Twi" and ''adwuma'' {{IPA|[adʑᶣu̘ma]}} "work", whereas {{IPA|[w]}} and simply labialized consonants are protruded.{{sfnp|Dolphyne|1988}} In Japanese, the {{IPA|/w/}} is compressed rather than protruded, paralleling the Japanese {{IPA|/u/}}. The distinction applies marginally to other consonants. In [[Kukuya language|Southern Teke]], the sole language reported to have a phonemic {{IPAslink|ɱ}}, the labiodental sound is "accompanied by strong protrusion of both lips",{{sfnp|Paulian|1975}} whereas the {{IPAblink|ɱ}} found as an [[allophone]] of {{IPA|/m/}} before {{IPA|/f, v/}} in languages such as English is not protruded, as the lip contacts the teeth along its upper or outer edge. Also, in at least one account of [[speech acquisition]], a child's pronunciation of ''clown'' involves a lateral {{IPA|[f]}} with the upper teeth contacting the upper-outer edge of the lip, but in ''crown'', a non-lateral {{IPA|[f]}} is pronounced with the teeth contacting the inner surface of the protruded lower lip.{{sfnp|Kelly|Local|1989|p=41}}

Some vowels transcribed with rounded IPA letters may not be rounded at all. An example is {{IPAslink|ɒ}}, the vowel of ''lot'', which in [[Received Pronunciation]] has very little if any rounding of the lips. The "throaty" sound of the vowel is instead accomplished with [[sulcalization]], a furrowing of the back of the tongue also found in {{IPAslink|ɜː}}, the vowel of ''nurse''.{{sfnp|Lass|1984|p=124}}

It is possible to mimic the acoustic effect of rounded vowels by narrowing the cheeks, so-called "cheek rounding", which is inherent in back protruded (but not front compressed) vowels. The technique is used by ventriloquists to mask the visible rounding of back vowels like {{IPA|[u]}}.{{sfnp|Sweet|1877|pp=14, 20}} It is not clear if it is used by languages with rounded vowels that do not use visible rounding.

{|class="wikitable" style="text-align:center"
|+Unrounded, compressed and protruded vowels
!
! Front
! Near-front
! Central
! Near-back
! Back
|-
! Semivowel
| {{IPA|j ɥ ɥʷ}}
|
| {{IPA|j̈ ɥ̈ ẅ}}{{sfnp|Pullum|Ladusaw|1996|p=191}}<ref>Or para-IPA {{angbr IPA|ɉ}}, {{angbr IPA|&#x1DF3E;}} ({{IPA|ɥ̶}}) {{angbr IPA|&#x1DF3F;}} ({{IPA|w̶}}).[https://www.unicode.org/L2/L2024/24049-ipa-support-letter.pdf]</ref>
|
| {{IPA|ɰ ɰᶹ/wᵝ w}}
|-
! Close
| {{IPA|i y yʷ}}
|
| {{IPA|ɨ ÿ ʉ}}<ref>Both {{IPA|[ÿ]}} and {{IPA|[ü]}} have been mentioned at various times in {{harvtxt|International Phonetic Association|1999}}, without comment on the implied difference in rounding.</ref>
|
| {{IPA|ɯ ɯᶹ/uᵝ u}}
|-
! Near-close
|
| {{IPA|ɪ ʏ ʏʷ}}
| {{IPA|ɪ̈ ʏ̈ ʊ̈}}
| {{IPA|ɯ̽ ɯ̽ᶹ/ʊᵝ ʊ}}
|
|-
! Close-mid
| {{IPA|e ø øʷ}}
|
| {{IPA|ɘ ø̈ ɵ}}
|
| {{IPA|ɤ ɤᶹ/oᵝ o}}
|-
! Mid
| {{IPA|e̞ ø̞ ø̞ʷ}}
|
| {{IPA|ə ø̞̈ ɵ̞}}
|
| {{IPA|ɤ̞ ɤ̞ᶹ/o̞ᵝ o̞}}
|-
! Open-mid
| {{IPA|ɛ œ œʷ}}
|
| {{IPA|ɜ œ̈ ɞ}}
|
| {{IPA|ʌ ʌᶹ/ɔᵝ ɔ}}
|}

Of the open-mid vowels, {{IPA|[œʷ]}} occurs in Swedish and Norwegian. Central {{IPA|[œ̈]}} and back {{IPA|[ʌᶹ]}} have not been reported to occur in any language.