Sound Meter: measure decibels with your Android phone

A decibel meter in your pocket

How loud is the construction site next door, the music at a party or the open-plan office? Sound Meter uses your phone's built-in microphone to measure the volume in decibels (dB) in real time. A gauge shows the current level, a chart shows how it changes, and the app keeps track of the minimum, maximum and average of each measurement.

Save and document measurements

Each measurement can be saved. In the history you see every recording with its values, duration and date, and you can rename, share or delete it. For documentation you download the measurement as an audio file and as a PDF report with a chart, the top values and timestamps – handy if you want to keep a record of recurring noise.

The app also measures in the background while your screen is locked. That is useful for noise at night, for example from traffic or a neighbor. A dark mode keeps the screen calm in the evening.

Calibrate for your phone

No two phone microphones are the same. The calibration dialog lets you shift the displayed value from −20 to +20 dB so it fits your device. The most reliable way is to compare with a professional sound level meter. Without one, set the reading to around 20–30 dB in a very quiet room.

Honest about accuracy

Smartphone microphones are designed mainly for voice, so the values can differ from professional sound level meters – especially at very low and very high levels. Sound Meter is a practical tool to get an idea of noise levels, compare situations and keep notes. It is not a certified measuring instrument.

What people use it for

• measuring ambient noise at home or in an apartment
• checking the volume of music, speakers and devices
• getting a feel for noise in the office or at work
• documenting noise at night
• an idea of construction or traffic noise

Want to know which levels matter? Read How loud is too loud? Measuring decibels with your phone.