The spelling of the word "smitham" represents a challenge due to the presence of phonemes that don't match one-to-one with their corresponding graphemes. Specifically, the "th" sound in the middle of the word is represented by the digraph "th," which can produce either a voiced or voiceless dental fricative, depending on the context. The IPA transcription of "smitham" is /smɪθəm/, with the first syllable pronounced as "s-m-i-th" and the second syllable pronounced as "ə-m." Achieving the correct spelling of "smitham" requires a strong understanding of English phonetics and phonology.