James Perrett wrote:It might help if you told us how the existing building is constructed - and presumably your are in the USA? Rockwool will help stop the sound from bouncing around inside a cavity but whether this will help in your case depends upon the exact construction.
Yes, I'm in the USA. The existing building is a two-story home with shallow foundation and light-frame construction, combination of stone and stucco.
I came across a new type of soundproofing involving broadband and subwavelength absorbers. They contain structures that reduce the thickness and weight of acoustic treatments, making them significantly better at absorbing acoustic energy at very low frequencies. Allegedly, walls can be made to subdue various types of noises, even those from the intense vibrations of MRI machines.
One researcher said the possibilities are endless since this type of noise mitigation method can be customized to suit nearly any environment: "The idea is that we can now mathematically design an object that can block the sounds of anything."
I wonder where the public might be able to customize and purchase such acoustic-silencing metamaterials because compared to the unsightliness and heaviness of today's sound barriers, these are lightweight, open, and beautiful and can be used as tiles or bricks to scale up and build sound-canceling, permeable walls.
YouTube Video - Acoustic Metamaterials
Article - Metamaterials: Soundproofing The Future
Research Paper - Air Transparent Soundproof Window
YouTube Video - Air Transparent Soundproof Window
YouTube Video - Demo Acoustic Metamaterial: Acoustic Enclosure
YouTube Video - Noise-Eliminating Materials | Yang Zhiyu
YouTube Video - Acoustic Metamaterials Group Demo (500-6000Hz)
YouTube Video - Acoustic Metamaterial Noise Cancellation Device
Profile - Researcher at the Department of Physics at Hong Kong University