Hi,
I tried again and again and finally I did this :
Line 1 of intercom has: cables as before Nuki + nuki blue + nuki yellow + nuki black + nuki green
Line 2 of intercom has: cables as before Nuki + nuki red + nuki orange + nuki purple
Nuki app → sounds → all disabled
Found the trick here : Help with Urmet 1133/14 - Discussion / Questions - Nuki Developers
Thank you again Rose Languste for all the time you spend with my problem 