noise reduction rating (NRR) have to be tested at several frequency bands for their ability to reduce noise. I had two pairs with me: Moldex Purafit (NRR-33)-one of my favorite foam earplugs for sleeping and Mack’s Flightguard (NRR-26) -reusable earplugs that are designed to block noise and help with airplane pressure changes.Įarplugs with a U.S. Would earplugs work against the humming noise? But, while I would definitely sleep with these headphones if necessary, I am a side sleeper, and I hadn’t even brought my special pillow. So yes, these noise cancellers pushed my hum below the threshold of hearing. Taking the headphones off, the obnoxious hum immediately came back. Well, I put on the QC35, turned them on, and-they did a fabulous job.ĭespite best efforts, I couldn’t make out the noise anymore. How do I get rid of this noise?įirst, I tried my Bose QC35 noise cancelling headphones.

Would you be able to sleep peacefully with that kind of noise? “OK,” I thought. This is what the microphone picked up close to the wall: (Note: Electricity in Vietnam is 220V/50 Hz. It turned out to be humming noise peaking at 50 Hz.

To better pinpoint the dominant frequencies, I recorded it and looked at its frequency spectrum: The room was generally quiet, otherwise I would perhaps only have noticed that noise at night.

How to get rid of white noise