The vowel sound in "wash" is the /ɑ/ sound, also known as the open back unrounded vowel.

The vowel sound in "nose" is the open-mid back unrounded vowel, represented by the symbol /o/. It is a rounded vowel produced with the tongue placed in the back of the mouth.

The vowel sound in "fox" is the short /ɑ/ sound. It is a low, back, unrounded vowel sound.

The accented syllable in the word "except" is the second syllable, of which the vowel is an open-mid front unrounded vowel, represented in IPA as /ɛ/. The entire pronunciation of except is /ik-sept/ (transcribed in IPA as /ɪkˈsɛpt/.

The vowel sound in "ego" is the "ee" sound, which is a close front unrounded vowel.