HOWL is a simple vocoder/synthesizer. It uses formants to simulate the human voice and a pitch-space keyboard to help you find interesting melodies.


• Simple synthesizer (just a sawtooth wave nothing too complicated okay)
• Simple vocoder (four parallel bandpass filters, a bit like the Klatt engine)
• Audiobus support, so you can pipe your own audio through the vocoder and/or send the output to other software
• Adjustable pitch-space keyboard
• Cool FX (bitcrush, reverb, vibrato and tremolo)

Download it today!

HOWL is also open source (check out the code at

What’s New

Version 2.2

iOS 11 support

Ratings and Reviews

4.1 out of 5
7 Ratings

7 Ratings

lostproductivity ,

Very nice

Plays well with AUM and Audioshare (Audioshare being a source). Just don't forget to play (and/or lock) it while filtering and turn the knobs down a bit so you can hear your source audio coming in. Very excited to further mangle more sound experiments.

Da Frog ,

Awesome app!

Really a thrill to use with all the modulation options at your fingertips on an iPad. Phenomenal touchscreen UI. I'm about to record a particularly grimey slurry of vowels and use that audio as the modulator for ableton's vocoder. It's gonna be funnnn....

ChrisE1G ,

A brilliant little formant synth app

Ok so this is (at least at the moment) free, so you could just download it and give it a try. It's a formant synth, two large areas for note/pitch and controlling vowels. You can definitely get that low Mongol voice sound thing going on with this. Great stuff.

I do wish this had Audiobus and/or IAA as it is such a great little synth and kinda deserves some AB/IAA love (pls dev?:)


Daniel Clelland
14.4 MB

Requires iOS 11.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© Protonome 2015


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