Sound Type Authority List

The Sound Type Authority List provides data values for the Sound Type element.

Silent
scope note: Use for audiovisual materials recorded without sound.

Silent and Sound
scope note: Use for audiovisual materials partially recorded with sound and partially recorded without sound. The bulk of the materials should be silent.

Sound
scope note: Use for audiovisual materials recorded with sound.

Sound and Silent
scope note: Use for audiovisual materials partially recorded with sound and partially recorded without sound. The bulk of the materials should be sound.

Source:

http://www.archives.gov/research/search/lcdrg/authority_lists/soundlist.html