Noise Insulation Properties

Noise Insulation Properties

Independent laboratory tests on OZ Roll® AR 400 domestic roller shutters have demonstrated that this product can reduce noise transmission through a window opening. The noise reduction benefits obtained in university tests varied significantly depending on the frequency of the noise source. For low frequencies between 100 Hz and 300 Hz this did not provide any benefits. However, for higher frequencies between 300Hz and 1250Hz the sound transmission loss was improved by 3-10 decibels. At higher frequencies (>1250Hz) the improvement in sound transmission loss with the roller shutter curtain down was typically greater than 10 decibels.

To understand how the change in sound levels (decibels) is perceived, the apparent change in loudness is shown in table 1

Table 1

Change in Sound level

Change in apparent loudness

3 decibels

just perceptible

5 decibels

clearly noticeable

10 decibels

half as loud

20 decibels

much quieter

To understand how some common noises compare with changes in sound levels (decibels) and the predicted apparent change in loudness refer to table 

Table 2

NoiseReduction in DecibelsPredicted subjective response
City traffic (10m from kerb)4 decibelsjust perceptible – clearly noticeable
Urban motorway (40m from edge)3 decibelsjust perceptible

Jet airliner flying at 300m

6 decibels

clearly noticeable

Dishes being washed (kitchen)10 decibels

perceived as half as loud

2 stroke whipper snipper at 7m7 decibelsclearly noticeable
2 stroke lawn mower at 7m4 decibels

just perceptible – clearly noticeable

Small dog barking at 5m9 decibelsclearly noticeable – perceived half as loud

Optimum noise reduction is achieved using an installation with silicone sealant applied between the head box and guides and the wall. To be effective the rest of the home must be sealed properly to ensure there are no air gaps which will allow sound to pass. These air gaps will significantly reduce the effectiveness of the roller shutter and noise reduction benefits will not be apparent

Notes: Noise reduction tests refer to noise reductions achieved in university tests through a closed sliding aluminium framed window with dimensions 1320*820mm. Fitted with a roller shutter (AR400 curtain) mounted ON WALL with silicone sealant applied under the head box and guides for optimum sealing to the wall. The tests only show noise reduction through the roller shutter and no allowance is made for other noise transmission paths such as gaps around doors, ventilation and air conditioning holes in ceilings etc.