title: Recording high quality speech during tagged cine-MRI studies using a fiber optic microphone.
abstract: 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.
authors.affiliation: Department of Diagnostic Radiology, University of Maryland Medical School, Baltimore, Maryland 21201, USA. mstone@umaryland.edu
authors.forename: Moriel S
authors.initials: MS
authors.lastname: NessAiver
authors.forename: Maureen
authors.initials: M
authors.lastname: Stone
authors.forename: Vijay
authors.initials: V
authors.lastname: Parthasarathy
authors.forename: Yuvi
authors.initials: Y
authors.lastname: Kahana
authors.forename: Alexander
authors.initials: A
authors.lastname: Paritsky
authors.forename: Alex
authors.initials: A
authors.lastname: Paritsky
mesh_terms: 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*