How to compare traffic noise at different windows

One room may seem much louder than another, but a passing truck or a running fan can skew a quick comparison. A consistent measurement can help you find out whether traffic noise is regularly louder at one window, or whether you just caught a noisier moment.

Use the Noise Meter to check the sound level through your device's microphone. For the fairest comparison, use the same device and repeat the measurements under similar conditions.

Compare noise at each window

1. Open the Noise Meter and allow microphone access when your browser asks. Set your phone or computer on a stable surface so you do not have to hold it while measuring.
2. Choose what you want to compare. To find the quieter place to sit or sleep, measure at the usual chair or bed location in each room. To compare noise near the windows themselves, measure at the same distance from each window, at about the same height.
3. Keep the setup consistent. Use the same device, microphone, orientation and room conditions each time. Decide whether the windows will be open or closed, then keep them that way for every reading. Keep interior doors and nearby fans or air conditioners in the same state too.
4. Take readings for the same length of time. At each location, watch the displayed level for about one minute. Note the readings at regular intervals, along with obvious events such as a bus or truck passing. Do not compare one quiet moment at one window with a loud vehicle at another.
5. Repeat the comparison. Take at least three rounds, ideally at a similar time of day. If possible, change the order of the rooms between rounds. This helps reveal whether a difference is consistent or just reflects changing traffic.

Write down the location, window position, time and readings. Even a simple note such as “living room, window closed, 8:30 a.m.” makes it easier to compare results later. Avoid putting a device outside or in a place where it could fall.

What the result means

One window has a higher reading in most rounds

That room or measurement point is consistently louder under the conditions you tested. The cause could be the window, the direction it faces, nearby traffic, or how sound reflects around the building. The reading shows the sound at your measuring point, not the window's sound insulation rating.

The readings are close or change places

You may not have a dependable difference between the locations, or the variation from traffic and background sound may be larger than the difference between windows. Repeat the test at another time, and keep the device in exactly the same position for each round. Treat small differences cautiously because a browser microphone is not a calibrated sound meter.

One location has occasional high readings

A few high readings may line up with a bus, motorcycle, truck or other brief sound. Note those events separately instead of treating a single peak as the room's usual noise level. If you care about interruptions, the peaks may still matter, even when the typical readings are similar.

Readings stay high when traffic is quiet

Another sound may be contributing, such as ventilation, a refrigerator, construction or people inside the building. Listen for the source and repeat the measurement when it is off, if you can do so safely. The meter measures the sound reaching its microphone, not traffic alone.

Make the comparison more reliable

1. Keep the microphone position fixed. A change in distance or direction can change the reading. Mark the device's place on a table or use the same stand in each room. Avoid covering the microphone with a case, hand or fabric.
2. Measure comparable periods. Traffic varies by time of day. Compare the rooms one after another, then repeat on another day at a similar time. Do not use readings taken during very different traffic conditions as if they were a direct test of the windows.
3. Control other sound sources. Keep music, television, fans and HVAC settings consistent. If you are checking how much traffic enters with a window open, keep the interior doors and other windows in the same positions too.
4. Use the same device and browser. Microphones and sound processing differ between phones and computers. Do not compare a phone reading in one room with a laptop reading in another. If microphone access is blocked, check Settings › Privacy & security › Microphone on Windows 11 or System Settings › Privacy & Security › Microphone on macOS, then allow your browser.

What a decibel reading can tell you

Decibels are a logarithmic measure, so a change in the number is not a simple percentage change in loudness. A difference of about 10 dB is often perceived as roughly twice as loud, though the sound itself and the listener affect perception. Smaller differences can be difficult to judge by ear, and a phone or computer microphone may not be accurate enough to treat a small change as meaningful.

Use the Noise Meter to compare relative sound levels with one device and a consistent setup. It cannot identify which part of the sound came from traffic, certify a window's sound rating, or replace a calibrated meter for formal measurements.