Had my window inserts for a few weeks now and I am very impressed by how much they have suppressed the sound outside! I am less than 20 feet from the road and there is a lot of traffic on the street near my apartment with people walking by and cars coming and going. I would hear people having conversations as they were walking by and realized I had no privacy in my room. Now that I have the window inserts, I no longer hear outdoor conversations and hardly hear cars (only supped up ones or a bus exhaust). I turned on my sweeper and couldn't hear it when I went and stood outside my bedroom window. I would recommend window inserts for anyone living in a city and having noise pollution creep into their apartments or homes!