When articulating the Khasi open 'a' sound, what specific phonetic context causes it to become more closed, and how is this distinct from its typical pronunciation?

The typical Khasi open 'a' sound is a low central unrounded vowel, articulated with the tongue body positioned low and centrally in the oral cavity, often phonetically transcribed as [a]. This represents its most open pronunciation. The specific phonetic context that causes this Khasi open 'a' sound to become more closed is the influence of an adjacent palatal or palatalized consonant. A palatal consonant is produced by raising the tongue body towards the hard palate, the roof of the mouth behind the alveolar ridge. A palatalized consonant is one that acquires a secondary articulation with the tongue body raised towards the palate. Whe....