Introduction Fire Performance Sound Transmission Sound Transmission Class of Wall Constructions Sound Absorption NRC Values Sound Absorption Coefficients Back to Index page

Tontine Sound Batts ACOUSTIC DESIGN MANUAL Cont. ..Sound Absorption As well as sound being absorbed, it may also be reflected from a solid surface. Reflected sound will increase the sound level on the source side of the solid. A material's ability to absorb sound is measured by its sound absorption coefficient, and is often expressed in terms of a Noise Reduction Coefficient (NRC) when comparing different products and surfaces. Sound absorption materials are not all alike and do not absorb sound of all frequencies equally well. Thus it is necessary to determine the sound absorption coefficient for each octave band. Testing of Tontine Polyester Insulation products for sound absorption coefficients using the Reverberation Room method were carried out by a NATA approved laboratory in accordance with Australian Standards. Samples were floor mounted with no air space behind the samples. ..NRC Values The table below shows the NRC Values for a number of the Tontine Sound Batt and Tontine Black Liner (data sheet in the ducting section) products. Product NRC Value   TSB 3 TSB 4 TSB 5 TBL 20/25 TBL 20/50 TBL 32/25 TBL 32/50 TBL 32/75 TBL 32/100 TBL 38/25 TBL 48/50 0.50 0.65 0.70 0.50 0.75 0.55 0.80 0.90 1.00 0.65 0.85 NRC values for the TBL range with perforated foil adhered to the product can be found in the Ducting section.