SHORT FRONT CLOSED UNROUNDED VOWEL [i]
In unstressed closed syllables, Tiberian Hebrew pataḥ is normally pronounced as a short i‑vowel.
SHORT FRONT CLOSED UNROUNDED VOWEL [iː]
In stressed and/or open syllables, ḥireq is pronounced as a long vowel [iː].
(in open or stressed syllable)
EXTRA LONG FRONT CLOSED UNROUNDED VOWEL [iː]
In a stressed closed syllable, ḥireq is pronounced as an extra long vowel [iːi].
(in stressed closed syllable)
SOURCES AND FURTHER READING
Khan, Geoffrey. 2020. The Tiberian Pronunciation Tradition of Biblical Hebrew. Cambridge: Cambridge and Open Book Publishers. §I.2.