The spelling of the word 'OTUN' is straightforward because it follows the rules of phonetic transcription. The word 'OTUN' is pronounced as ɒtʌn, with the first syllable pronounced as 'ot', and the second syllable pronounced as 'un'. The symbol 'ɒ' represents the open back rounded vowel, while the symbols 't' and 'n' represent the voiceless dental and alveolar consonants, respectively. The vowel 'ʌ' represents the schwa sound, which is a neutral vowel sound. Overall, 'OTUN' is pronounced as "ot-un" following standard phonics rules.