Aluplast 4000 series, when using a standard double glazed unit, can reduce sound by 25db when compared to a single glazed window. If the noise level is reduced by 10 dB, we perceive this as a 50% reduction in noise. This means that when replacing an old single glazed window with a high quality window from Green Innovation results in a 25 dB reduction in sound pressure, meaning the perceived sound would be 18.75% of what it previously was - or a reduction of 81.25%.