Plants, soil, trapped air, and moisture in the soil are great acoustic insulators. Studies have shown that green walls can reduce ambient noise by up to 40 decibels, an important benefit to those who work or live close to noisy streets, highways and airports. Because the decibel scale is logarithmic, every 10-decibel reduction equals a tenfold decrease in intensity.
If you live on a busy street, ambient noise levels may average 75 decibels. The design for a quiet office may target 60 decibels, a quiet urban neighborhood may average 40 decibels at night and a quiet library may seek to operate below 40 decibels. If you are an architect, landscape architect, or contractor, it is easy to see how much additional peace and tranquility you can bring to your client by including a vertical garden in your building plan.