Voice changer

• Deeper and Higher move the pitch 4 semitones and keep the voice's timbre, so it sounds like a lower or higher voice, not a slowed-down or sped-up one.
• Male to female and Female to male move the pitch 5 semitones and the formants, the resonances that make a voice sound like a bigger or smaller body, 3 semitones the same way.
• Chipmunk and Monster move everything 8 semitones together, the cartoon way: tiny and squeaky, or huge and slow-sounding.
• Robot multiplies the voice by a 50 Hz tone (a ring modulator), the metallic sound of film robots. Telephone keeps only 300 to 3,400 Hz, the band a phone line carries, with a little distortion.

Playing a recording faster makes it higher and shorter at once. The voice changer keeps the length: Signalsmith Stretch, the open-source library behind the pitch changer, cuts the sound into short overlapping slices and moves each slice's frequencies, here in your browser. Its formant control then puts the voice's resonances back where they were, or moves them on purpose, which is what separates a convincing deeper voice from a slowed-down tape.

Every voice is heard as it plays, through the same engine that makes the download, so what you hear is what you get.

This changes recordings, not your voice as you speak on a call or a stream. A live voice changer for calls is on the list of tools we may build next: vote for it there.