The correct spelling of the word "Master vibrator" can be a bit confusing due to the various ways the sound "v" can be spelled in English. However, using the International Phonetic Alphabet (IPA), we can see that the sound is represented by the symbol /v/. Therefore, the spelling of "Master vibrator" is phonetically transcribed as /ˈmæstər ˈvaɪbreɪtər/. It is important to use correct spelling in professional settings to avoid any misunderstandings or inappropriate connotations.