I have the same thing installed in my basement ceiling joists. It wasn't Corning through, it was Johns Manville. It works well for keeo mids and highs from leaking up through the basement ceiling. This should not be used for bass traping, rather, it should be for sound-proofing. Sound Absorbtion and Sound Proofing are two different topics. If you want to absorbtion, go with the Rock Wool or Rigid Fiberglass.