Can a plexiglass window block enough noise?

[@DougGrinbergs]

Spectrograms might also be interesting

[@soundproofist]

True! I need to work on my spectrogram skills first.

[@drizmans]

90db is insanely high for a residential area, im surprised theyre allowed to do that since you should be wearing ear protection at those levels

[@soundproofist]

Totally agree. I captured some video recently where a carpet cleaning service in a van was making a racket that you could hear for 1/4 mile. The van was parked one block away...I didn't know what it was nor where it was coming from, so I started walking around the neighborhood to find it. When I finally found the source, it measured at 103 decibels. Seems like residents should be given advance notice to prepare for ear-splitting blasts like that.

[@user-fy7ri8gu8l]

I mean, what else are they going to do? Let the next downpour result in flooding? In these circumstances, they should just put out warning pamphlets with earplugs, they're dirt cheap, but it has to get done.

[@soundproofist]

@@user-fy7ri8gu8l This was not a "ban the drain cleaners" video. Of course this maintenance needs to get done, just like we need street cleaners, garbage collection, etc. It was a good opportunity to make a noise test, though, since so many of these machines make dangerously excessive noise.

[@aram8495]

Really nice video! Just a thought, I'm wondering if the decibel readings between the panels might've increased due to outdoor sounds reflecting off the plexiglass?

[@soundproofist]

Thanks. I also wondered if there was any effect from the first iPhone (inside the gap) leaning against part of the window, whereas the iPhone outside the plexiglass was in my hand. That was actually out of necessity because the 2nd iPhone's battery was completely run down and I had to plug it in to use it. But you might be right: there's a possibility that some of the louder noise in the gap could have come from the plexiglass reflecting it back towards the original window. In another video, I built a noise-absorbing insert to put on each side of the window in the gap. Those noise absorbers were not used in this test. So the next time I get the opportunity, I should test the decibels with and without the noise-absorption placed inside that gap (about a 2-inch wide space).

[@User.k3431]

In my opinion, acrylic glass can't fully block out thumping and low vibrational noises from very large vehicles. I live in Toronto and the streetcars are just absolutely horrendous in terms of their noise. I wanted to buy a noise/vibration meter but I can't find one within a reasonable price range. Is there any meters that can read vibrations on market? Do any Android apps exist? Thanks 🙏

[@soundproofist]

I agree about the plexiglass. It helps to block or reduce mid-frequency noise, like people talking on their cell phones outside, or a car engine idling (but not revving). The low vibrational noise affects the whole structure, not just the window. And as you saw in the video, the plexiglass could reduce decibels, but not the vibration and low frequency. If you look closely above the decibel readings on these smartphones, you'll see a frequency meter, which averages about 200Hz. That's pretty low frequency (though not the very lowest), and I use that as a gauge to see how much vibration is still passing through (vibration=low frequency). If the app displayed something like 800Hz, I'd assume that higher frequencies were passing through. In another video, I tested a vibration app (not just a decibel app) agaist a coffee grinder, but many of those vibration apps are geared towards the Richter scale, and the streetcar vibration isn't going to show up in a significant way. Offhand, I don't know of an inexpensive hand-held vibration meter. There are some high-end ones like Brüel & Kjær, but those are definitely not within budget. I'll keep looking.

[@JP5466]

1/8" plexiglass will attenuate low frequency noise, but you have to have a very large air gap in between the outer window and the plexiglass, and of course everything has to be sealed air tight. I did an experiment with my basement window (24"x48"). The window sill is 15" deep. I made a plug with 1/8" Lexan and framed it with 3/4" plywood and 1/2" cork sheeting (used as a gasket around the inside part of the frame). There is also 1/2" cork sheeting covering inside the entire window sill; top, sides and bottom. In the summer I have a few cars coming down my street playing LOUD bass music, which I find annoying as hell. Sometimes the music is so loud that if you were outside you would have to yell to communicate with someone. I tested the plug at different distances from the outer window; 5", 10" and the full 15". The 5" distance worked okay, the 10" distance was better, but the 15" distance attenuated the loud bass by about 95%. I know many ppl do not have the luxury of a 15" deep window sill, but I just wanted to post this info here as an FYI.

[@TheGodfather101]

holy shit 90 db? any louder can cause your eardrums to perforate.... also stc is not a great metric. oitc is more pertinent.

[@soundproofist]

It was pretty loud. I never heard what it sounded like outside (too busy trying to capture this video inside). Thanks for the tip about OITC. Do you have any suggestions on how to calculate that from the data I collected already? Or is there an app that does it?