The spelling of the word "INTROPTA" can be explained using the International Phonetic Alphabet (IPA). The first syllable "IN" is pronounced as "ɪn", meaning a short vowel sound. The second syllable "TROP" is pronounced as "trɒp", with the "o" being a mid-back rounded vowel sound. Finally, the third syllable "TA" is pronounced as "tə", meaning a schwa vowel sound. Altogether, "INTROPTA" is pronounced as "ɪn.trɒp.tə".