Editing Cardinal vowels (section)

{{Short description|Reference vowels used to describe the sounds of languages}}
{{IPA notice}}

[[Image:Cardinal vowels-Jones x-ray.jpg|thumb|200px|X-rays of Daniel Jones' {{IPA|[i, u, a, ɑ]|cat=no}}.]]
[[Image:Cardinal vowel tongue position.png|thumb|200px|Highest tongue positions of cardinal front and back vowels]]
[[Image:Cardinal vowel chart-accurate(png).svg|200px|thumb|Diagram of relative highest points of tongue for cardinal vowels]]
[[Image:Cardinal vowel chart-common(png).svg|thumb|200px|The "''cardinal vowel quadrilateral''", a more commonly seen schematic diagram of highest tongue positions of cardinal vowels]]

'''Cardinal vowels''' are a set of reference vowels used by phoneticians in describing the sounds of languages. They are classified depending on the position of the tongue relative to the roof of the mouth, how far forward or back is the highest point of the tongue, and the position of the lips (rounded or unrounded).

A cardinal vowel is a [[vowel]] sound produced when the [[tongue]] is in an extreme position, either front or back, high or low. The current system was systematised by [[Daniel Jones (phonetician)|Daniel Jones]] in the early 20th century,<ref>{{cite book|last1=Jones|first1=Daniel|title=An English Pronouncing Dictionary|date=1917|publisher=Dent|location=London}}</ref> though the idea goes back to earlier phoneticians, notably Ellis<ref>{{cite book|last1=Ellis|first1=A.J.|title=The Alphabet of Nature|url=https://archive.org/details/alphabetnatureo01elligoog|date=1845|location=Bath}}</ref> and Bell.<ref>{{cite book|last1=Bell|first1=A.M.|title=Visible Speech|url=https://archive.org/details/visiblespeechsc02bellgoog|date=1867|location=London}}</ref>