Lately I’ve been experimenting with iPod Touch applications for recording sound. Generally it’s necessary to use a headset to make a recording, but my goal is to figure out a practical way to bypass the headset with an input for a high quality microphone. While unsuccessfully testing my Audio Technica AT822 stereo mic as an input for the iPod Touch I captured an interesting glitch within the application I was testing.

The low frequency waveform (shown in the image at the left) played at regular intervals while I had the microphone attached. Perhaps it’s some sort of communication protocol for headset controls. I removed the DC offset, but otherwise left it as it was. Perhaps I’ll try playing it back at some higher frequencies to see it’s useful for anything musically.

iPod Touch Glitch