Arduino voice changer turns you into [Vader]

Halloween is just around the corner, so of course we’re looking forward to a bunch of awesome costumes put together by Hackaday readers. In an effort to match his voice to his costume, [Phil Burgess] over at Adafruit (and former Hackaday alumnus) put together an Arduino-powered voice changer to give his voice the gravitas of [James Earl Jones] or the lightheartedness of a member of the Lollipop Guild.

If you’ve ever played with a turntable, you’ll know playing a 33 RPM record at 45 or 78 RPM turns your treasured copy of Dark Side of the Moon into a lighthearted aural experience with a pitch that is much too high. Likewise, playing a single at 33 or 16 RPM means those once dulcet tones are now recordings of tormented souls in an acoustic hell.

[Phil]‘s voice changer operates on the same principle by recording sounds from a microphone into a circular array and playing them back at a different rate; faster if the desired effect is a Munchkin, and slower if this year’s Halloween costume will be a Sith lord.

The completed build incorporates a 10k pot to dynamically change the timbre of the voice changer, as well as an Adafruit Wave Shield to play back a few pre-recorded sounds of lightsabers clashing. In all, a very cool project for your Halloween costume that’s also a very good introduction to DSP and real-time audio modifications with a microcontroller.


  1. bzroom says:

    Very nicely done. I didnt know this shield was capable of real time signal processing like that. Super convincing too. NICE JOB.

  2. NewCommentor1283 says:

    this shield does not do ANY processing. it is only a “soundcard” and a “flashdrive”… the AVR/arduino does all the processing

    PS: this does not work as well with my hardware but is still fun.

    in my hardware (screw the 23$ shield!), i use R2R ladder for DAC and use direct port writes. “PORTA=low;PORTC=hi;”

    also, it DOES work on an ATMega1280… but not on an ATMega32 (40 pin DIP)

    its the damm 22$ substitute for resistors that does not work with the Mega. go figure

    watching people use a creditcard to buy what they already have… priceless!

  3. Arthur says:

    James lives in our town.
    James Earl Jones, FYI was the voice for Darth Vader.

  4. bothersaidpooh says:

    A Halloween hack for you I have…

    Soldering ninja are at you, young Padawan.

    This is pretty neat, however there are single chips which do this (or at least used to be)..
    I think they are pretty much extinct now unless you search the charity shops for a voice changing toy with corroded batteries and perform brain surgery to extract the chip.

    • Jeff Nme says:

      The simplest circuit I’ve seen for this vioce effect uses a 555 and an opto-isolator to chop the voice and give the robotic effect.
      The effect is variable by using a pot in the r/c circuit that regulates the 555 astable frequency.

  5. limpkin says:

    I hope HaD gets some money for all the sponsoring they are doing these days…

  6. Bill Gander says:

    Lost me at the wave shield. Why not put that in the title? Arduino + Waveshield +amplified microphone=scary voice changer. Also “Halloween City” or whatever local gypsy halloween store you have in your area have voice changers for $5.00 that might fit the more budget minded tweaker. There is a resistor (R4) iirc that can be fiddled with. A 555 one like Jeff mentioned can add interesting Dahlek modulation with a robot voice changer :) EXTERMINATE your supply of candy into my bag :D

  7. Jim M says:

    Could someone point me to a tutorial on how to build one just for the voice using a 555?

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 96,710 other followers