How to change male voice to female on call (iphone) or any?

I need to talk to someone in female voice and if they call back also i need to do the same, i'm male, please be considerate in answering, no jokes please. I use iphone 4s. So is there any way, and it must be an on call live one, not just recorded and changing. Those who can explain please answer only. And please explain clearly and how to do that too

There's no good software to change a male voice to a female one. All you can do is raise the pitch of your voice, which will only sound like a voice with its pitch raised, i.e., not female.