The spelling of the word "bobb" may seem strange, but it can be explained using IPA phonetic transcription. The first sound, /b/, is a voiced bilabial plosive, where the lips come together to make a "b" sound. The second sound, /ɑ/, is an open back vowel, making an "ah" sound. The final sound, /b/, is another voiced bilabial plosive. So, the word "bobb" is spelled the way it is to represent these specific phonetic sounds in the English language.