The exemplar work looks like a good
approach, as Jort has provided Matlab code, I would imagine that
it could be readily tested for your particular case.
Another approach to think about, if you have a section of isolated
noise in your audio recording, is the pioneering work by Ephraim
& Malah.
They produced the statistical method of spectral noise estimation
and removal ... the trick in your case would be to make sure that
you are using an analysis window which is long enough to be able
to capture the low frequency components of your noise source.
You can find a SPDemo application in the downloads section on
their web page :
http://sipl.technion.ac.il/
Matt
On 09/20/2012 12:19 AM, Jort Gemmeke wrote:
Dear Kyle,
I dont have experience with MRI scanner sounds in particular,
but it seems like such a structured interfering source should be
a good match for the exemplar-based source separation techniques
I have been using over the past few years. You can find more
information on my website,
www.amadana.nl , as well as a
demo (matlab) and some links to related techniques that may be
of use.
Feel free to contact me directly if you think this can be of
use, then we can give it a try.
Jort Gemmeke
Postdoctoral Researcher
KU Leuven, ESAT-PSI Speech group
Date: Wed, 19 Sep 2012 16:59:06 -0400
From: Kyle Jasmin <kyle.jasmin.11@xxxxxxxxx>
Subject: Subtracting regularly repeating sounds
--bcaec501654d005be504ca1447c5
Content-Type: text/plain; charset=ISO-8859-1
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