Noise cancellation in an MRI environment is difficult due to the high noise levels that are in the spectral range of human speech. This paper describes a two-step method to cancel MRI noise that combines operations in both the time domain (correlation subtraction) and the frequency domain (spectral noise gating). The resulting filtered recording has a noise power suppression of over 100 dB, a significant improvement over previously described techniques on MRI noise cancellation. The distortion is lower and the noise suppression higher than using spectral noise gating in isolation. Implementation of this method will aid in detailed studies of speech in relation to vocal tract and velopharyngeal function.
REFERENCES
1.
M. S.
NessAiver
, M.
Stone
, V.
Parthasarathy
, Y.
Kahana
, and A.
Paritsky
, “Recording high quality speech during tagged cine-MRI studies using a fiber optic microphone
,” J. Magn. Reson. Imag.
23
, 92
–97
(2006
).2.
J. M.
Inouye
, X.
Feng
, C. H.
Meyer
, K. Y.
Lin
, K.
Borowitz
, T.
Altes
, T.
Kovach
, W.
El-Nahal
, K.
Pelland
, and S. S.
Blemker
, “New technique to assess velopharyngeal function with multi-planar real-time MRI
,” in Proceedings of the 12th International Congress on Cleft Lip/Palate and Related Craniofacial Anomalies
(2013
).3.
J. M.
Inouye
, C. M.
Pelland
, N. M.
Fiorentino
, W. G.
El-Nahal
, K. Y.
Lin
, K. C.
Borowitz
, and S. S.
Blemker
, “A 3D model of the human soft palate muscle function during speech: Implications for surgical repair of cleft palates
,” in Proceedings of the 11th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering
(2013
).4.
A.
Niebergall
, S.
Zhang
, E.
Kunay
, G.
Keydana
, M.
Job
, M.
Uecker
, and J.
Frahm
, “Real-time MRI of speaking at a resolution of 33 ms: Undersampled radial flash with nonlinear inverse reconstruction
,” Magn. Reson. Med
. 69
(2), 477
–485
(2013
).5.
A. D.
Scott
, R.
Boubertakh
, M. J.
Birch
, and M. E.
Miquel
, “Adaptive averaging applied to dynamic imaging of the soft palate
,” Magn. Reson. Med.
70
(3), 865
–874
(2013
).6.
E.
Bresch
, J.
Nielsen
, K.
Nayak
, and S.
Narayanan
, “Synchronized and noise-robust audio recordings during realtime magnetic resonance imaging scans
,” J. Acoust. Soc. Am.
120
, 1791
(2006
).7.
S. A.
Counter
, A.
Olofsson
, H.
Grahn
, and E.
Borg
, “MRI acoustic noise: sound pressure and frequency analysis
,” J. Magn. Reson. Imag.
7
, 606
–611
(1997
).8.
Z.
Wu
, Y.
Kim
, M. C.
Khoo
, and K. S.
Nayak
, “Evaluation of an independent linear model for acoustic noise on a conventional MRI scanner and implications for acoustic noise reduction
,” Magn. Reson. Med.
(published online).9.
E.
Bresch
, Y.
Kim
, K.
Nayak
, D.
Byrd
, and S.
Narayanan
, “Seeing speech: Capturing vocal tract shaping using real-time magnetic resonance imaging
,” IEEE Sign. Process. Mag.
25
, 123
–132
(2008
).10.
FOMRI-III Noise Cancellation System, http://www.optoacoustics.com/medical/fomri-iii (Last viewed February 5, 2014).
11.
S.
Boll
, “Suppression of acoustic noise in speech using spectral subtraction
,” IEEE Trans. Acoust. Speech Sign. Process.
27
, 113
–120
(1979
).12.
sox-Sound eXchange, http://sox.sourceforge.net (Last viewed February 5, 2014).
13.
X.
Feng
, J. M.
Inouye
, S. S.
Blemker
, K. Y.
Lin
, K. C.
Borowitz
, T.
Altes
, T.
Kovach
, W.
El-Nahal
, C. M.
Pelland
, and C. H.
Meyer
, “Assessment of velopharyngeal function with multi-planar high-resolution real-time spiral dynamic MRI
,” in Proceedings of the 21st Annual Meeting of the International Society for Magnetic Resonance in Medicine, Program 1228
(2013
).14.
audacity software, http://audacity.sourceforge.net (Last viewed February 5, 2014).
15.
http://bme.virginia.edu/muscle/cleftpalate/noisecancellation.html (Last viewed February 5, 2014).
© 2014 Acoustical Society of America.
2014
Acoustical Society of America
You do not currently have access to this content.