The spelling of the word "brown bells" can be explained using the International Phonetic Alphabet (IPA) as /braʊn bɛlz/. The first syllable "brown" is spelled with the letter "b" and the diphthong "ow" which represents the sound /aʊ/. The second syllable "bells" is spelled with the letters "b" and "ll" which produce the consonant blend /bl/ and the vowel sound /ɛ/. So, the correct spelling of the word "brown bells" accurately represents its pronunciation according to the IPA.