A palatogram is an image of the region of the upper surface of the vocal tract contacted by the tongue due to a consonant. The best way to obtain such an image is to coat the tongue with a mixture of equal parts olive oil and activated charcoal powder and record the resulting transfer of pigment.


The process is as follows:



Fig 1: Diagram showing relative position of the elements required to record the palatogram.




Fig 2:  Palatogram; still image digitized from video.  Orientation:  Upper teeth are shown at top and reflected in the mirror at bottom.