I have lived in quite a few apartments and stayed in countless hotel rooms where traffic noise was waking me up several times a night.
Over time, I have developed a good understanding of what works to block out enough noise to help me fall and stay asleep.
Whether you have traffic noise keeping you awake at night or are a shift worker who has to sleep during the noisiest hours, this post is for you.
The two best tool sets I have found to block out traffic noise while sleeping are the following:
- Foam earplugs + mid-pitch white noise to boost earplug performance
- Active noise cancelling headphones + shaped white noise to boost headphones performance
When I stay somewhere and traffic noise becomes a problem (e.g., city apartment or hotel room), I use both tool combinations regularly.
At night I am mostly a side sleeper, which makes foam earplugs my first choice.
But, I have also gotten in the habit of afternoon napping, and I almost always nap lying on my back—wearing active noise cancelling headphones and playing white noise.
What frequencies is traffic noise made of?
To understand why I use these tool combinations and how to optimize them, let’s take a look at what traffic noise is actually composed of.
A while ago, I recorded about an hour of noise bleeding into my bedroom and then looked at the frequencies of individual noise events.
The apartment is in a small alley about 50 ft. from a main road with traffic going on day and night (a lot less but still). Close to the alley entrance is an intersection with traffic lights, so every couple of minutes vehicles stop and then start again.
I measured the bedroom background noise level at 30 decibels (dBA), which is reasonably quiet.
Individual noise events, however, reach 50 dB at certain frequencies and at times even >60 dB.
And herein lies the problem: everything is relatively quiet, and then you have trucks, cars and motorbikes revving up their engines, random honking, screeching brakes etc.
I analyzed about 20 minutes of my recordings in detail, identified individual noise events that stood out and looked at their dominant frequencies.
In the following table, I have subsumed and categorized individual noise events to make it easier to look at frequency ranges:
Now, all of these were noises that stood out and bothered me.
The most prevalent and annoying noise sources were the low-bass trucks, which at times caused building resonances, and the various mid-frequency vehicle horns that just came out of nowhere and startled me.
This table holds the key as to how my noise blocking tools help me against traffic noise and how I optimize them.
In the chart below you can see one individual noise event (at night).
Notice how at most frequencies the noise level is really low and then there is a certain range that goes up. The peak (125 Hz) is at 50 dB, while the overall noise level is 32 dBA (pushed up to this level by the peak).
But it is not only me: several studies have shown that sound level differences of 15 dB or more often cause arousals, i.e., wake people up or cause a shift from deep sleep to a lighter sleep stage.
And here is a short bedroom traffic noise sound sample. (Best listened to using headphones):
Foam earplugs plus mid-pitched white noise
As you can see from the table above, the traffic noise in my bedroom encompasses a broad frequency range from 30 (mostly 40) up to 11000 Hz (over time).
And, foam earplugs are good at reducing noise across almost the complete range of human hearing.
Because they are also comfortable, they are my preferred tool to block traffic noise when I am sleeping on my side.
Furthermore, foam earplugs (comparative review if you need ideas for earplugs) are quite good at reducing the noise from trucks, motorbikes, and vehicles in general.
In terms of low-frequency noise reduction, they are better than earmuffs but not as good as the best active noise cancelling headphones.
In addition to foam earplugs, I also use a white noise machine, mostly the Lectrofan Classic.
While foam earplugs make everything quieter, car horns and screeching brakes can still stand out.
To mask these pesky mid-and-high frequency noise intruders and soothe myself to sleep, I often play mid-pitched (and sometimes high-pitched) white noise (e.g., noises #5 to #8 on the Lectrofan Classic) at around 55 decibels.
Basically, these days I just cycle through the white noises and adjust the volume until it feels right.
When special circumstances call for it (loud hotel rooms, nearby parties), I might increase the white noise sound level to up to 70 decibels.
But note, I wear earplugs when I do that!
Note: For the lower-pitched vehicle noises, I rely mainly on the earplugs. Depending on your situation, you can also select a lower pitched brown noise, which helps against normal vehicle noise. But, the speaker of virtually all white noise machines doesn’t go low enough to mask truck noise.
What if your significant other doesn’t like earplugs and louder white noise or if you have a small child in your room?
In that case, wear headband headphones on top of foam earplugs and play white noise (using the myNoise app; see below for details).
For my favorite models, take a look at the headband section of my post The Best Headphones and Earbuds for Sleeping.
Active noise cancelling headphones plus tailored white noise
Quality active noise cancelling headphones (ANC headphones) are the most formidable tool for reducing low-frequency traffic noise—or you can say bass-noise—I know of.
I find low-frequency rumbling and resonances caused by trucks and other large vehicles among the most stressful traffic noises.
Just listen to the following sample with headphones “to appreciate” the resonances:
I take an early afternoon nap five out of seven days, and in the early afternoon there tends to be a lot of this heavy traffic.
(Mind you, some trucks are still passing through at night.)
So I nap with noise cancelling headphones. Currently, I nap with the Sony WH-1000XM3 and they do a great job at getting rid of the trucks.
Wearing ANC headphones, I hear virtually nothing of the bass that comes with the traffic noise in my bedroom.
To learn more about how my two favorite ANC headphones perform against bass noise (and the limits), read this post on blocking bass noise.
How about the honking?
The horns and the screeching noises are reduced as well, but here the headphones need help.
And this help comes again in the form of white noise—white noise shaped to emphasize the mid-and-lower-treble frequencies.
Frequent readers of NoisyWorld know that I love the app myNoise.
I use it mostly on an iPad (myNoise iOS), but it is also available as myNoise for Android. The basic app with the generator White Noise & Co is free, and this is all you need for the purpose of masking traffic noise.
(I have gotten the complete iOS package including all nature sounds. They sound great and I wanted to support the developer.)
myNoise is among the very few white noise apps in which you can precisely shape your noise with an equalizer.
When using ANC headphones, I almost completely remove the bass frequencies from the white noise because the headphones take care of this so well, and I feel lighter when I don’t have to hear any bass.
This is how I shape the noise to take a nap with the Sony headphones:
For some reason, I nap while lying on my back. I just prefer that. In this position, I find the headphones very comfortable.
At night, I sleep mostly on my side and for that over-the-ear headphones are less than ideal.
I would love to have the headphones’ low-frequency noise cancelling performance at night as well, but foam earplugs are just more comfy for side sleeping.
However, for back sleepers these ANC headphones are the best anti traffic noise tool I have come across so far.
Note: I have used ANC headphones at night as well. Using a horseshoe pillow, I can sleep on my side. Still, I find foam earplugs more comfortable.
Are you wondering why I don’t use smaller in-ear noise cancelling headphones at night?
I have some very good and comfortable ones (the Bose QC20): They do help but are not as good against the low bass of the trucks, and they don’t muffle enough mid-frequency noise (e.g., the horns) for my taste. They are an option but I would have to play white noise pretty loud.
I have looked at other in-ear models, but so far I haven’t found anything better.
If you went outside and measured the frequency spectrum of traffic noise, you would get a very different result compared to what you get in a bedroom or hotel room with average noise isolation.
This is because windows and doors reduce the mid-and-high frequency parts of traffic noise a lot better than the bass frequencies.
What you are often left with is low-frequency noise, resonances, and intermittent mid-or-high-frequency noises that stand out, such as honking, screeching noises, and impact noises.
A bedroom that is quiet in general can make these noises stand out even more.
To block out this kind of traffic noise and allow you to fall and stay asleep, my recommended tool sets are the following:
- Foam earplugs in combination with mid-pitched white noise played through a white noise machine (or a sleep headband worn on top of the earplugs).
- Active noise cancelling headphones + tailored white noise (app) that contains virtually no bass frequencies and emphasizes the mid-frequencies.
I use both the earplugs for night-time sleeping (on my side) and the headphones for daytime napping (on my back).
Because I am particularly troubled by bass noise, in terms of performance, I would prefer the headphones, but I do better with foam earplugs when sleeping on my side.
Please let me know in the comments how it goes.