3. Nasal vowels

From NLD, page 695 1st edn, page 749 2nd edn:
There are three nasal vowels in Lakota: aŋ, iŋ, uŋ.
The sounds of these vowels are comparable to, but not identical with, certain English vowels followed in the same syllable by a nasal consonant plus another consonant. Thus the sound of iŋ and aŋ may be compared with the vowels in hint and hunt. (Note that the comparison is to the sound of the vowel only, without the following consonants.) American English has no equivalent for Lakota uŋ. Examples of Lakota nasalized vowels are híŋ hair, háŋ yes, húŋku his/her mother.
Nasalization of iŋ is sometimes rather weak and some speakers omit it in certain words. A typical example is the word kiŋ pronounced ki by some speakers.
Various materials erroneously claim that there is a fourth nasal vowel, oŋ. There is no such vowel in Lakota language. A sound similar to oŋ occurs only in fast speech when it replaces the suffix –pi (see p. 771, 0).
There are three nasal vowels in Lakota: aŋ, iŋ, uŋ.
The sounds of these vowels are comparable to, but not identical with, certain English vowels followed in the same syllable by a nasal consonant plus another consonant. Thus the sound of iŋ and aŋ may be compared with the vowels in hint and hunt. (Note that the comparison is to the sound of the vowel only, without the following consonants.) American English has no equivalent for Lakota uŋ. Examples of Lakota nasalized vowels are híŋ hair, háŋ yes, húŋku his/her mother.
Nasalization of iŋ is sometimes rather weak and some speakers omit it in certain words. A typical example is the word kiŋ pronounced ki by some speakers.
Various materials erroneously claim that there is a fourth nasal vowel, oŋ. There is no such vowel in Lakota language. A sound similar to oŋ occurs only in fast speech when it replaces the suffix –pi (see p. 771, 0).