Call and listen without showing on the screen

My idea is to make a program for listen a voice on cellular phone with symbian OS, without showing any number and picture and even light during ringing and conversation on the screen. With remotely activation on specified phone number entered before, only microphone will be activated and everything in the room the caller will listen. When I give this phone to somebody, and when call to this phone the microphone will be activated and without knowing of the “giving person” I will listen everything, but hidden))

I expect answer soon!

Thank you!

See More: silent or hidden call