A USC Multispeaker speech production articulatory datasets of vocal tract MRI video
 the 'USC 75-Speaker Speech MRI Database'  is a new freely-available speech production data set with accompanying software  tools:
https://www.nature.com/articles/s41597-021-00976-x

These data contain 2D sagittal-view RT-MRI videos along with synchronized  audio for 75 subjects performing linguistically motivated speech tasks,  alongside the corresponding raw RT-MRI data. The dataset also includes
3D volumetric vocal tract MRI during sustained speech sounds and  high-resolution static anatomical T2-weighted upper airway MRI for each  subject. 

Other speech production datasets of articulatory data that are also freely available  include  a TIMIT articulatory data corpus and emotional speech production data, all available from:  https://sail.usc.edu/span/resources.html