Keeping out street noise

noise reductionsound-proofing

While I live on the 7th floor, the noise coming from street level is significant. Small motorcycles with their mufflers taken off race by all day long, constantly, and even at this level they can be ear piercingly loud. While it rarely wakes me up, it sometimes feels like noise pollution is impacting the quality of my sleep.

My bedroom has wall-to-wall, floor-to-ceiling glass, so there is a rather large surface that needs to be treated. Outside, there is a balcony with a ceiling that will be reflecting sound. Inside, we have a thick curtain that does not seem to be doing much by the way of keeping sound out.

As we rent, replacing for double or triple glazed windows isn’t an option. So I’m wondering how to approach this.

Should I build a wall of wooden frames with insulation ‘wool’ stuck inside? Every morning removing those frames would become a nuisance no doubt, and storing them during monsoon season possibly a hassle.
Should I stick sound insulation foam (the studio kind) to the outside of the windows, praying they come off the window once we move out?
Stick insulation wool up on the balcony ceiling?
Hang a vinyl curtains in front of the windows on the outside?
Ruin our view by putting plants everywhere along the edge of the balcony, so the leaves help in reflecting sound.

Best Answer

Your best answer is to move. <grin>

Replacing the glass with windows designed for this can help, but IMHO they don't do enough to be worth their high price.

You could try exterior mounted bamboo slat sun blinds (they would be easy to raise and lower) But I think they would only drop it by 3-4 dB.

A better and cheaper thing to try would be to glue old carpet to the underside of the balcony above you. Would look ugly as sin, but 2 foot long strips a foot wide, with 3 inches glued to the upper balcony, and the remainder hanging down would put a big dent on sound reflections.

It should be possible to create a device that has a microphone that you fasten to the outside of the window at the center, and a device inside that picks up the mike signal and vibrates the inner window out of phase.

While this would work for sound that is coming straight on, with the peak arriving at the entire pane essentially simultaneously, coming from below there will be considerable delay between a wave crest reaching the lower and upper part of the window. (An 8 foot window is about 1/120 of a second corresponding to about 120 Hz (approximating sound at 1000 ft/s) ) To cope with this you would need to have a phase difference between the bottom and top of the window.


It's been/being done.

https://www.nytimes.com/2020/07/11/science/windows-street-noise.html#:~:text=Researchers%20in%20Singapore%20have%20developed,Nanyang%20Technological%20University%20in%20Singapore.

Denoise is selling them now. But only claims 90% reduction. That's about 30 dB https://denoize.com/residents/ Costs are about 500 english pounds per square meter. Window has to be replaced, not a a retrofit to existing windows.

However a search did not reveal anything as simple as what I described above.