The spelling of the word "TOMSON" is a common variation of the surname "THOMSON" in some English-speaking countries. The correct pronunciation of this name is /ˈtɒmsən/ using the International Phonetic Alphabet (IPA) phonetic transcription. The sound "th" is replaced with the voiced sound "m" in this spelling, making it a phonetically irregular variant. It is important to note that this spelling variation may cause confusion and errors in official documents, so it is recommended to use the standard spelling.