Austrian Composer Peter Ablinger has transformed a child speaking so that it can be played as MIDI events on a mechanically-controlled piano, making the piano a kind of speech speaker. Via Matrixsynth, the readers at Hack a Day get fairly involved with how this may be working.

It seems not quite accurate to describe this as vocoding in the strictest sense, so much as a simple transformation to a (much) lower frequency resolution – that is, the 88 keys of the piano. Ablinger, for his part, describes the events as “pixels.” It’s pretty extraordinary that without a bandpass filter, you get something approximating the noisy sibilance of the speech, but this seems to be the result of having lots of events (that is, lots of resolution in terms of time). Edit: Listening again, the short answer to how you can hear so much of the voice through the piano seems to be, you can’t; the original is almost certainly mixed in. It’s nonetheless an interesting effect, and I’d like to hear the piano on its own. In other words, the basic process is, 1) convert the sound spectrum of the recorded voice to a series of MIDI events, and 2) play back the translated MIDI file. You can see that the MIDI playback is accomplished with Pd (Pure Data) running on a Windows Linux/KDE netbook, though it’s not clear what was used to do the original conversion. (The screen shot with side-by-side audio and MIDI appears as though it may be for demonstration purposes, only.)

Correction: The work is absolutely done in custom software developed by the composer in Pd (Pure Data). It’s an ideal tool for the job, and free and open source. I wouldn’t dare try to replicate the results here, but this is fantastic inspiration for playing with sound in Pd.

One Windows tool that’s capable of the job is TS Audiotomidi, as observed by Hack a Day spacecoyote. Whether or not that’s what’s at work here – and it may well be – that utility is itself interesting. Edit: Yeah, far more likely the whole thing was done in Pd. And Pd should be up to the task.


Of course, this is to say nothing of the lovely work done on the mechanical piano. It’s a beautiful piece. Here’s hoping some government bureaucrats got the message of the declaration. Now, we just need a chorus of something really loud – say a thousand trumpets – shouting out the Universal Declaration of Human Rights.