The acoustic performance of glazing assemblies is defined by the average noise reduction factor RW with the measure dB (according to EN 20 140, EN ISO 717 and EN ISO 140).

RW is determined by measuring and comparing to a reference curve related to human perception and represents an average sound insulation over the relevant frequencies.

Specific correction factors adapt the noise reduction factor RW to particular sound sources: C for high frequencies and Ctr for low frequencies (e.g. typical traffic noise).

High sound transmission loss – good sound insulation – is desired in many commercial curtain wall applications. Limiting sound transmission through glazing requires review and testing of the entire glazing system.

Laminated glass and insulating glass tend to provide better acoustic performance because the laminate dampens vibration and the air space limits sound transmission.

For more information, contact Guardian's Technical Advisory Center.