The working principle of these programs is the alteration of the timbre is unrecognizable. You can speak with the voice of a person of another gender, age, nationality, apply effects, presence in a certain place, etc.
The first of these programs – "Fake voice". Install it from the link below, run it and open settings. Choose the tone, effects, and features fake voice according to your desire.
The second program – Scramby. A link to the installation file is also provided. The set includes 23 of the timbre of voices and 46 additional effects. You can turn on and off sounds that simulate a particular environment. For use in programs that support voice chat settings (for example, "Skype" instead of the default sound card, use the virtual – Scramby.
Programs of this kind applies Voice Changer. After installation, select the program skin, pull the levers and set the tone that you like.