- Tout is pronounced 'tou' (silent final '[t]' with a short '[u]' sound before)
- Toute/Toutes is pronounced 'touTT' (stressed final '[t]' with a short '[u]' sound before)
- Tous is pronounced 'tou:SS' (stressed final '[s]' with a long '[u:]' sound before)
With a few exceptions:
- The final 't' of tout is pronounced when it is followed by a vowel to ease the speech: 'à touTT âge' (at any age), 'touTT un chacun' (every single one), etc.
- The final 's' of tous is NOT pronounced when followed by 'les' in 'dans tous les cas' (in any case) but stressed in all other cases, especially when you want to express countable/uncountable difference like in:
- Ils sont tous nus 'touss' (All of them are naked)
- Ils sont tout nu 'tou' (They are fully naked)
Just a few points:
- ils sont tout nus
When the subject is feminine and the adjective starts with a consonant sound, the adverb is 'feminized' to ease pronunciation:
- elle est tout entière / tout heureuse (non-aspirate H)
- elle est tout honteuse (aspirate H)
- elle est toute nue
- elles sont toutes nues
Not sure about tout and tous, but 'toute' and 'toutes' are indeed pronounced the same.