Recording high quality speech during tagged cine-MRI studies using a fiber optic microphone.
OBJECTIVE
To investigate the feasibility of obtaining high quality speech recordings during cine imaging of tongue movement using a fiber optic microphone.


METHODS
A Complementary Spatial Modulation of Magnetization (C-SPAMM) tagged cine sequence triggered by an electrocardiogram (ECG) simulator was used to image a volunteer while speaking the syllable pairs /a/-/u/, /i/-/u/, and the words "golly" and "Tamil" in sync with the imaging sequence. A noise-canceling, optical microphone was fastened approximately 1-2 inches above the mouth of the volunteer. The microphone was attached via optical fiber to a laptop computer, where the speech was sampled at 44.1 kHz. A reference recording of gradient activity with no speech was subtracted from target recordings.


RESULTS
Good quality speech was discernible above the background gradient sound using the fiber optic microphone without reference subtraction. The audio waveform of gradient activity was extremely stable and reproducible. Subtraction of the reference gradient recording further reduced gradient noise by roughly 21 dB, resulting in exceptionally high quality speech waveforms.


CONCLUSIONS
It is possible to obtain high quality speech recordings using an optical microphone even during exceptionally loud cine imaging sequences. This opens up the possibility of more elaborate MRI studies of speech including spectral analysis of the speech signal in all types of MRI.
NessAiver
Moriel S
MS
Department of Diagnostic Radiology, University of Maryland Medical School, Baltimore, Maryland 21201, USA. mstone@umaryland.edu
Stone
Maureen
M
Parthasarathy
Vijay
V
Kahana
Yuvi
Y
Paritsky
Alexander
A
Paritsky
Alex
A
D000162:Acoustics; D000328:Adult; D004867:Equipment Design; D005240:Feasibility Studies; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D013018:Sound Spectrography / Q000295:instrumentation*; D013060:Speech; D013382:Subtraction Technique; D014059:Tongue / Q000502:physiology*