Is ʕ̞ equivalent to the semivowel articulation of ɑ?

Question

Wikipedia claims that Ladefoged & Maddieson (1996) p. 323 states that ʕ̞ is equivalent to the semivowel articulation of ɑ.

Is this true?

If so, why?

If not, what is the false premise behind this claim?

Edit:

https://en.wikipedia.org/wiki/Semivowel#Classification

Answer 1

It is not true, Ladefoged & Maddieson do not make that claim there or anywhere else. If you found such a Wiki page you could check the history to see who made up this attribution (it's always best to give a link to a Wiki claim since there are billions of pages and it's impractical to check them all).

It is true that L&M do discuss the idea that there might be "non-syllabic vowel-like sounds that might be considered as semivowels", or "semivowels corresponding to mid-vowels". The examples involve short diphthongs, where the entire syllable nucleus is packed under a single mora. North Saami presents an example, where there is a surface distinction between [ĭe], [ie] and [je], the former being a short diphthong, the second being a long dipthong, and the third being a glide plus vowel sequence. The dialect that I worked on does not have short [ŏa], the mid diphthongs are all long, but some dialects also have [ŏa, ĕa]. These transcriptions mean that you have two vocoids and perceptually the second element, the lower vowel, is more prominent, leading to the impression of a shortened first vowel.

In the table of Nepali examples provided by L&M, they do in fact include underlying forms with both /ai/ and /ia/, /ao/ and /oa/. The transcribed outcomes are [ja, aj, aŏ, ŏa], meaning that supposed desyllabification or at any rate shortening affects the higher vowel, and does not affect /a/.