Reconsidering the IPA Vowel Quadrilateral

The IPA vowel chart is among one of the very first tools we learn as linguists. Linguistics students are asked to memorise the vocalic symbols and their position in the chart. Specifically, they are taught that the vertical axis of the chart corresponds to vocalic height distinctions and that the horizontal axis of the chart corresponds to frontness distinctions. These axioms (plus others) are imparted without allowing for any critique.
 
However, since the very inception of the IPA, the characteristics of the vowel chart in particular have been put under the spotlight of an attempted debate (which seems to have been dismissed by the IPA committee of the time), initiated by at least two authors: Göran Hammarström in 1973 and Michael Ashby in 1989. More recently, Geoff Lindsey has criticised the traditional IPA vowel chart (by also invoking Peter Ladefoged's own critique) and proposed an alternative that commits to being a better representation of the vocalic acoustic space as we understand it from the measurements of formants.
 
This talk will review the critiques of these and other authors and the main characteristics of the acoustic and articulatory space of vowels in support of Lindsey proposal. Specifically, we will see how the overall acoustic vocalic space of human languages is triangular and not trapezoid (as Daniel Jones would want us to believe) and how a triangular vowel chart solves the issue of descriptive phoneticians when they are faced with the choice of picking a vowel symbol for a particular vocalic sound.