They have plenty of tested data on their products and minimal BS.

Here’s a sample of their acoustical panel data.

These Echo Barrier roadside and construction noise barriers are wildly popular but they are ineffective for many reasons.

They don’t provide test reports. No comparisons like-for-like. No documentation. The install is to cover a sheet of drywall with it before hanging.

Here’s another dubious product with great marketing: Green Glue. As far as I can tell the compound and sealant are “okay” as acoustical sealants. They likely won’t harden over time and can provide some damping between layers at a wall. However

Even with published specs from manufacturers, it’s worth having a bit of skepticism. For instance here’s Sonopan’s brochure for architects

These are some of the considerations when we are making changes to our urban environments.

Here are max noise levels should we aim to achieve:

I used to live next to an arterial road and I couldn’t open the windows during the day or night because traffic would be too noisy for me to hear practically anything inside.

TV, radio, another person talking.
All unintelligible.

Unfortunately if you live in an apartment and have #noise issues with your neighbours there is nothing feasible you can do to reduce it except to get them to make less noise. Or move out. #acoustics

EVs will also not reduce road noise on anything but local streets. At speeds of 35km/h and above, tire noise becomes more significant

(Bottom blue line is passenger vehicle engine noise; everything else is louder)