Smock & Schonthaler
Industrial Insulation Sales, Inc.
2320 Warfel Ave. • Erie, Pennsylvania 16503 • Toll Free: 1-800-734-8771 • Local Phone • (814) 456-4222 • Fax: (814) 456-8346


Use: to reduce noise reflection. To dissipate noise energy.

Physical Properties: Porous fibrous and sometimes covered with protective membranes. Noise enters the absorber and is partly dissipated (abosrbed) within the material. Some is transmitted. Some is reflected. Absorber performance is expressed as a decimal value. A perfect absorber is rated at 1.00. The higher the decimal value the more effective the absorber will be.

Effectiveness is expressed as NRC (Noise Reduction Coefficient).

NRC: Percentage of acoustical energy absorbed calculated as an average of laboratory test data at several frequencies.

Noise Reduction Coefficients of Materials
Brick, unglazed
Concrete block
1/8" pile carpet
5/16" pile carpet and foam
Concrete floor
Plaster, smooth finish
Plywood paneling, 1/4" thick
Water surface (as in swimming pool)
1" thick fiberglass curtain
3" thick "SONEX" wedge foam
4" thick smooth surface foam
4" thick metal panel