Hidayat al-Qari

The place of articulation of ḥolem is the root of the tongue and the place of swallowing, which is the place of articulation of א̇ה̇ח̇ע̇, and it moves over the surface of the entire mouth. Take note that if somebody were to investigate carefully their places of articulation, he would have something like the knowledge necessary as to what is first in position and what is last.

Translation from Khan (TPTBH II.L.2.15.1)

Hidayat al-Qari

The total number of vowels is seven: אֹ ,אִ ,אֵ ,אֶ ,אַ ,אָ and אֻ. From within these seven vowels the letters ו ,ה ,א, and י are pronounced. From qameṣ, pataḥ and segol ʾalef and he are pronounced, as in עַמֶּיךָ ,עֲבָדֶיךָ and קָשֶׁה. If the he (in קָשֶׁה) were elided, the segol (by itself) would indicate its existence, just as the qameṣ in עַמְּךָ ,שִׁמְךָ and עֲבָדֶיךָ indicates the existence of ʾalef or he in full orthography ... Ḥolem indicates the existence of vav, as in שׁוֹמֵר ,זוֹכֵר and the like.

Translation from Khan (TPTBH II.S.4.2)