User:Just granpa/vowels

https://www.mq.edu.au/about/about-the-university/our-faculties/medicine-and-health-sciences/departments-and-centres/department-of-linguistics/our-research/phonetics-and-phonology/speech/acoustics/speech-acoustics/vowel-spectra

http://www.fb10.uni-bremen.de/linguistik/dpng/sites/default/files/dokumente/Durand2005TenseLax-TheEnglishVowelSystemAndPhonologicalTheory.pdf

	Front	Central	Back
Close	i y	ɨ ʉ	ɯ u
Near-close	ɪ ʏ		ʊ
Close-mid	e ø	ɘ ɵ	ɤ o
Mid	e̞ ø̞	ə	ɤ̞ o̞
Open-mid	ɛ œ	ɜ ɞ	ʌ ɔ
Near-open	æ	ɐ
Open	a ɶ	ä	ɑ ɒ

	Front	Central	Back
Close	i ⓘ y ⓘ	ɨ ⓘ ʉ ⓘ	ɯ ⓘ u ⓘ
Near-close	ɪ ⓘ ʏ ⓘ		ʊ ⓘ
Close-mid	e ⓘ ø ⓘ	ɘ ⓘ ɵ ⓘ	ɤ ⓘ o ⓘ
Mid	e̞ ⓘ ø̞ ⓘ	ə ⓘ	ɤ̞ ⓘ o̞ ⓘ
Open-mid	ɛ ⓘ œ ⓘ	ɜ ⓘ ɞ ⓘ	ʌ ⓘ ɔ ⓘ
Near-open	æ ⓘ	ɐ ⓘ
Open	a ⓘ ɶ ⓘ	ä ⓘ	ɑ ⓘ ɒ ⓘ

Open glottis	[t]	voiceless (full airstream)
	[d̤]	breathy voice
	[d̥]	slack voice
Sweet spot	[d]	modal voice (maximum vibration)
	[d̬]	stiff voice
	[d̰]	creaky voice
Closed glottis	[ʔ͡t]	glottal closure (blocked airstream)

Kensiu, spoken in Malaysia and Thailand, is claimed to be unique in having true-mid vowels that are phonemically distinct from both close-mid and open-mid vowels, without differences in other parameters such as backness or roundedness

In the last few decades it has become apparent that phonation may involve the entire larynx, with as many as six valves and muscles working either independently or together. From the glottis upward, these articulations are:

1. glottal (the vocal cords), producing the distinctions described above
2. ventricular (the 'false vocal cords', partially covering and damping the glottis)
3. arytenoid (sphincteric compression forwards and upwards)
4. epiglotto-pharyngeal (retraction of the tongue and epiglottis, potentially closing onto the pharyngeal wall)
5. raising or lowering of the entire larynx
6. narrowing of the pharynx