Two Methods of Mechanical Noise Reduction of Recorded Speech During Phonation in an MRI devic

0363068 - ÚT 2012 RIV SK eng J - Journal Article
Přibil, J. - Horáček, Jaromír - Horák, Petr
Two Methods of Mechanical Noise Reduction of Recorded Speech During Phonation in an MRI devic.
Measurement Science Review. Roč. 11, č. 3 (2011), s. 92-98. ISSN 1335-8871. E-ISSN 1335-8871
R&D Projects: GA ČR GA102/09/0989
Institutional research plan: CEZ:AV0Z20760514; CEZ:AV0Z20670512
Keywords : speech processing * noise reduction * NMR imaging
Subject RIV: BI - Acoustics
Impact factor: 0.418, year: 2011

The paper presents two methods of noise reduction of speech signal recorded in an MRI device during phonation for the human vocal tract modelling. The applied approach of noise signal cleaning is based on cepstral speech analysis and synthesis because the noise is mainly produced by gradient coils, has a mechanical character, and can be processed in spectral domain. Our first noise reduction method is using real cepstrum limitation and clipping the “peaks” corresponding to the harmonic frequencies of mechanical noise. The second method is coming out from substation of the short-time spectra of two signals recorded withal: the first includes speech and noise, and the second consists of noise only. The resulting speech quality was compared by spectrogram and mean periodogram methods.
Permanent Link: http://hdl.handle.net/11104/0199174