PHARYNGEALIZED VOICELESS ALVEOLAR PLOSIVE [tˁ]
Tiberian Hebrew ṭeth sounds like English "t" pronounced emphatically. For those familiar with Arabic, it is pronounced like the letter ṭā (ط). To pronounce this, To pronounce this letter, constrict your throat and make your tongue concave to create an open cavity in the mouth while pronouncing "t".
SOURCES AND FURTHER READING
Khan, Geoffrey. 2020. The Tiberian Pronunciation Tradition of Biblical Hebrew. Cambridge: Cambridge and Open Book Publishers. §I.1.9.