Hightened or Heightened: How To spell?

The word Hightened is misspelled against Heightened, which is past tense of "Heighten"

Word contains consecutive vowels 'EI' in between alphabets h & ghtened is misspelled as 'I' as letter 'E' is phonetically ignor
Wrong Spelling:  h-i-ghtened 
Correct Spelling:  h-ei-ghtened 
Find more wrongly spelled words of Heightened to spell it well.