The spelling of the word "DEAM" primarily depends on the pronunciation of its sounds. In IPA phonetic transcription, "DEAM" is spelled as /di:m/, with the symbol /d/ indicating a voiced dental plosive, /i:/ representing the long vowel sound of "ee", and /m/ indicating a voiced bilabial nasal. Therefore, the spelling of "DEAM" is a reflection of the sounds that make up the word, and the phonetic transcription helps to accurately represent its pronunciation.