The spelling of the word "SUMU" is quite straightforward in terms of its phonetic transcription. The first syllable "SU" is pronounced as /su/ with the letter "u" being pronounced with a sound close to "oo". The second syllable "MU" is pronounced as /mu/ with the letter "u" being pronounced with a sound close to "u" in the word "put". Overall, the word "SUMU" is pronounced as /su.mu/, with stress on the first syllable "SU".