Rathbun is a surname that can be spelled phonetically as /ræθbʌn/. The first syllable "rath" rhymes with "bath" and is pronounced with the vowel sound "æ" as in "cat". The second syllable "bun" is pronounced with a short "u" sound as in "fun". The letter "th" in "Rathbun" is pronounced as a voiceless dental fricative, similar to the "th" in "think". In summary, the spelling of "Rathbun" reflects the pronunciation of each phoneme in the word.