Using MRI to image the moving vocal tract during speech

Magnetic Resonance Imaging (MRI) has been used to measure the shape of the vocal tract during speech in several recent studies. Its safety to the subject, high quality imaging of soft tissue, and the ability to select relatively thin imaging planes at any angle are significant advantages over other imaging methods used for speech research. The most significant disadvantage is the long exposure time. As a result most studies have focused on obtaining high-resolution images of the vocal tract volume for static sounds, such as vowels [l], fricatives [5,6], nasals, the closed phase of plosives [7] and liquids [3,7]. In this paper we will describe our method of obtaining MR images of a moving vocal tract in which we post-synchronise the MR data using a recorded speech signal and thus reconstruct the images without using the MR machine’s built-in processing.