The correct spelling of "Oscar Ferdinand Telgmann" is ['ɒskər ˈfɜːdɪnənd ˈtɛlɡmən]. The phonetic transcription shows that the first name is pronounced with a short "o" sound, followed by the stressed syllable "fer" with a long "e" sound. The last name is pronounced with a short "e" sound followed by a stress on the second syllable "gman" pronounced with a soft "g". By using the correct IPA phonetic transcription, we can communicate the correct pronunciation of the name.