I use these clips with a MTS extension and I can hear the sound of that clips.
Some body has a solution for that situation.
Some body tell me to use a program that change the MTS to MP4.
Adobe do not have a simple solution.
Do you mean you can hear sound, but you can not see video? How did you import the clips in to Premiere? It is possible that you don't need to convert the files. Depending on the camera, and how the files are stored, you may just need to do the import again, but this time use 'media browser' in Premiere, to import them. For many camera files, it is important to use the media browser when importing, and NOT using drag and drop or file and import.