Voice distortion box
A voice distortion box or voice changer is a device which disguises a voice over the telephone or other medium. This technology may be implemented by hardware, software, or combination of the two.
Using voice changing technology, a person can change the sound of their voice so it appears to be the opposite gender, incorporates various sound effects, accents and mythical beings (for example, a leprechaun voice).
Regardless of the method used, the ultimate aim is to conceal the identity of the speaker from their audience. This is generally considered to be a form of stealth, deception or humor.