The spelling of the word "OIZN" can be explained using the International Phonetic Alphabet (IPA) phonetic transcription. The first sound "O" is pronounced as "oʊ", which is a diphthong. The second sound "I" is pronounced as "ɪ", which is a short vowel sound. The third sound "Z" is pronounced as "z", which is a voiced consonant. The last sound "N" is pronounced as "n", which is an unvoiced consonant. Therefore, the correct spelling of the word is "OIZN", which is pronounced as "oʊɪzn".