Here's one article you could look at:

Burris, C., Vorperian, H., Fourakis, M., Kent, R., and Bolt, D. (2014). Quantitative and descriptive comparison of four acoustic systems: vowel measurements, Journal of Speech Language and Hearing Research, 57, 26-45.

Jeff Knox

I would look at the publications list of any entity that does significant speech research or NLP research. Places that come to mind: MIT speech laboratory Haskins Laboratories, David Pisoni's Lab at U of Indiana, AT&T Bell Labs, Microsoft, IBM, Carnegie Mellon University, Ray Kent's Lab. University of Edinburgh, Queens University of Belfast (I think), Johns Hopkins, Peter Ladefoged's Lab (he's died but I think the lab still exists in his name). These are just a few for starters. I'm sure there are more.

Hello Swapnil,

This is a fascinating question, but one that has defied technological advancements. Ronnie has mentioned quite a number of systems and noted that there are more. Yes, there are many more, depending on the kind of information you want (fo characteristics, spectral structure, formant frequencies, aerodynamic data, etc). One thing I can assure you is that you can never get to truly define a vowel (the phonological entity) via these physical representations of a speech sound. Ronnie mentioned Ladefoged. If you look at Ladefoged's work, you'll find that these objective physical representations of speech sounds do not reflect the auditory experience we register listening to the sounds. In fact, Ladefoged stated that instruments are only a help, but the final arbiter in all phonetic studies is the trained ear of an experienced phonetician. (Cf. Ladefoged, P. (1963): Some physiological parameters in speech, Language and Speech, Vol. 6, pp 109 - 119; Also see Ladefoged, P. (1964): A phonetic Study of West African Languages. Cambridge University Press). All technologies in hearing research are based on the Pythagorean string ratio theory (6th century B.C.), Ohm's law (1844), and Helmholtz's resonance theory (1877). In a recent paper, it has been proved experimentally from the mechanical standpoint that all these theories are false, for which reason no one has been able or can explain hearing by acoustic data. (cf. Essien (2018): The mechanical invariance factor in musical acoustics and perception (revisited), In American Journal of Modern Physics, Vol. 7.1 pp 1-13. I hope this gives you a realistic platform for your search and expectations.