Kyle,The task reminds me of some work done by colleagues of mine, separating the components heart sound signals from stethoscope recordings. In their case they wanted to keep the repeating part rather than suppress it, but the basic characteristics of the sound - regular but slowly varying - are a good match.
M. G. Jafari, F. L. Hedayioglu, M. T. Coimbra and M. D. Plumbley. Blind source separation of periodic sources from sequentially recorded instantaneous mixtures. In Proc 7th International Symposium on Image and Signal Processing and Analysis (ISPA 2011), Dubrovnik, Croatia, 4-6 Sept. 2011, pp 540-545, 2011.
F. L. Hedayioglu, M. G. Jafari, S. S. Mattos, M. D. Plumbley, M. T. Coimbra. Separating sources from sequentially acquired mixtures of heart signals. In Proc IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2011), Prague, pp 653-656, May 22-27, 2011. http://dx.doi.org/10.1109/ICASSP.2011.5946488
Best Dan On 19/09/12 21:59, Kyle Jasmin wrote:
Dear all, I wonder if anyone has successfully removed the sound of a helium pump from auditory recordings made in an MRI scanner. It occurs regularly (every 1s), and changes over time (Praat thinks it is a formant with downward trajectory). Any advice is appreciated on subtracting regularly repeating sounds would be appreciated. With thanks, Kyle Jasmin Speech Communication Laboratory, UCL Institute of Cognitive Neuroscience & Laboratory of Brain and Cognition, National Institute of Mental Health
-- Dan Stowell Postdoctoral Research Assistant Centre for Digital Music Queen Mary, University of London Mile End Road, London E1 4NS http://www.elec.qmul.ac.uk/digitalmusic/people/dans.htm http://www.mcld.co.uk/