MPEGs that have mixed image and sound will not have their sound imported in the software.
IMPORTANT: Only MPEG1 can be imported into Toon Boom Studio. Toon Boom Studio does not support MPEG2 and MPEG4.
Only export a file that you plan to import into Toon Boom Studio to MPEG1 if you intend to use the image component and not the sound.
Mac OS X (all)
Toon Boom Studio 7