Subject: Re: onset detection From: robert gjerdingen <r-gjerdingen@xxxxxxxx> Date: Wed, 26 Dec 2007 11:31:05 -0600 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>On Dec 25, 2007, at 5:57 AM, Andrew McGuiness wrote: > First, the script looks for negative slope in the energy curve of > the sound, with energy calculate by averaging 100 millisecond > blocks, to eliminate very local fluctuations. If the sound file is > recorded clean, with no spill, this works well to identify the > general area of the onset. > Andy, For a counter example, you might look at an old paper of mine, “Smooth” Rhythms as Probes of Entrainment,” _Music Perception_ 10 (1993): 503-508 (<http://faculty-web.at.northwestern.edu/music/ gjerdingen/Papers/PubPapers/SmoothRhythms.pdf>). There the perceived onsets occur at positive-to-negative zero crossings of the second derivative of energy. This would be in a region of all positive slope, if I'm not misunderstanding your method. Best wishes for the Holidays, Bob Gjerdingen Northwestern Univ. School of Music