watermark.freesound.audible.wav

the text 'http://freesound.iua.upf.edu' made with noise of an audible frequency. you can see it looking at the spectrogram. In Audacity, for example, select the spectrum view instead of the more commonly used waveform view. To get a decent resolution the spectrogram should have a relatively narrow FFT band (1024 or above), results are best in grayscale. The original stereo audio file was produced with GNU/GPL Enscribe 0.0.4 by Jason Downer, then converted to a single channel with Audacity