Limp mass barrier has long been used to add mass inside floor/ceiling and wall assemblies.
Acoustic Curtains, Kinetics Noise Control - Kinetics Noise Control
Noise Control and Privacy, Home and Home Theater - Kinetics Noise Control
Noise Control Curtains, Kinetics KNC - Kinetics Noise Control
Class A Fire-Rated, Pipe & Duct Wrap - Kinetics Noise Control
Kinetics Noise Control, Manufacturer - Kinetics Noise Control
Mass Loaded Vinyl MLV Sound Barrier with PSA - 1/8 x 4.5' x 30
Acoustic Curtains, Kinetics Noise Control - Kinetics Noise Control
SilentCurtain™ Acoustic Curtain
Noise Control Curtains, Kinetics KNC - Kinetics Noise Control
Class A Fire-Rated, Pipe & Duct Wrap - Kinetics Noise Control
NOISEBLOCK™ Barrier Walls - Kinetics Noise Control