Cardinal Vowels
The Cardinal Vowels are a set of reference vowels established by the British phonetician Daniel Jones to provide a consistent calibration system for describing and transcribing the vowels of any language. They are not vowels of any particular language but a measuring grid — phonetic anchors against which actual vowels can be located.
The eight primary cardinal vowels
Jones defined eight primary cardinal vowels at the extremes of the human vowel space, numbering them in a fixed order: [1] [i], [2] [e], [3] [ɛ], [4] [a], [5] [ɑ], [6] [ɔ], [7] [o], [8] [u]. CV1 [i] is the most close and front position the tongue can take without producing friction; CV5 [ɑ] is the most open and back; CV4 [a] the most open and front; CV8 [u] close, back, and rounded. The remaining values divide the front and back peripheries into roughly equal auditory steps. Jones recorded the eight on gramophone disc for His Master's Voice in 1917, and the recordings remained the standard training reference for British phoneticians for decades.
The vowel quadrilateral
The cardinal vowels are conventionally plotted on a four-sided figure — the vowel quadrilateral — with tongue height on the vertical axis (close at top, open at bottom) and tongue frontness on the horizontal axis (front at left, back at right). The same diagram structures the vowel section of the IPA chart, where any vowel symbol's position represents an articulatory–auditory target.
Secondary cardinal vowels
A secondary set of eight inverts the lip-rounding of the primary series: rounded counterparts of CV1–CV5 ([y], [ø], [œ], [ɶ], [ɒ]) and unrounded counterparts of CV6–CV8 ([ʌ], [ɤ], [ɯ]). Together the sixteen vowels span the periphery of the vowel space.
Status in modern phonetics
Ladefoged showed in the 1960s that the cardinal vowels function as auditory rather than strictly articulatory targets, so the system is now treated as a perceptual reference grid. It remains the framework underlying the IPA vowel chart and most descriptive phonetic transcription.
References
- Jones, D. (1917). English Pronouncing Dictionary. Dent.
- Ladefoged, P., & Johnson, K. (2014). A Course in Phonetics (7th ed.). Cengage Learning.
- International Phonetic Association (1999). Handbook of the International Phonetic Association. Cambridge University Press.