The spelling of the surname "Mumpower" can be explained using IPA phonetic transcription. The first syllable is pronounced /mʌm/, with a short "u" sound and a nasal "m" sound. The second syllable is pronounced /paʊər/, with a diphthong "au" sound and a schwa sound. The overall spelling reflects the English language's inconsistent pronunciation rules, as the "o" is silent and the "e" at the end is not pronounced. The spelling of Mumpower may vary, but its pronunciation remains consistent based on the phonetic transcription.