The spelling of the word "Robenson" can be explained using the International Phonetic Alphabet (IPA). The first sound represented is the "r" sound /ɹ/. This is followed by the "oh" vowel sound represented by /o/. The consonant "b" sound is represented by /b/ and the following "eh" vowel sound is represented by /ɛ/. The final sound represented is the "n" sound /n/. Therefore, the correct spelling of this word is "Robenson" with the IPA transcription /ɹoʊbɛnsən/.