If you want to change the voice of the person who is calling you during a real phone call, then Call Voice Changer is the best app for you. It is a free app that can be downloaded on your Android device, and it will allow you to transform the voice in real time. The quality of the audio will be excellent, and you can record your voice in high quality so that you can share it with friends and family.

In order to do this, you can select from a list of voices that you have stored in your phone, and apply to them the effects you want to. You can make an old lady sound like a baby, and a boy like a girl, or a robot, and even a devil.

Now, you can make some hilarious prank phone calls to your friends and family.