About this app

"Decibel X" is one of very few sound meter apps on the market that has highly reliable, pre-calibrated measurements and supports frequency weightings: ITU-R 468, A and C. It turns your phone device into a professional sound meter, precisely measures the sound pressure level (SPL) all around you. This extremely useful and beautiful sound meter tool will not only be an essential gadget for many uses but also bring you a lot of fun. Have you wondered how quiet is your room or how loud is a rock concert or sport event? "Decibel X" will help you answer all of those.

WHAT MAKES "DECIBEL X" SPECIAL:

- Trusted accuracy: the app is carefully tested and calibrated for most devices. The precision is matching with real SPL devices
- Frequency weighting filters: ITU-R 468, A, B, C, Z
- Spectrum analyzer: FFT and BAR graphs to display real time FFT. Those are very useful for frequency analysis and musical tests. Real time predominant frequency is also displayed.
- Powerful, smart history data management:
+ Recording data can be saved into a list of history records for future access and analysis
+ Each record can be exported as hi-res PNG graph or CSV text via sharing services
+ Fullscreen mode to give overview the whole history of an record
- Dosimeter: NIOSH, OSHA standards
- InstaDecibel to capture your dB report overlaid on photos and easily shared via popular social networks (Facebook, Instagram, etc.).
- Beautiful, intuitive and carefully crafted UI design

OTHER FEATURES:

- Standard time weightings (Response Time): SLOW (500 milliseconds), FAST (200 milliseconds) and IMPULSE (50 milliseconds)
- Trimming calibration from -50 dB to 50 dB
- Standard measurement range from 20 dBA up to 130 dBA
- Spectrogram
- HISTO graph for plotted history of the recorded values
- WAVE graph with 2 display modes: Rolling & Buffer
- Real time scale level chart
- Display Current, Average/Leq, and Max values with both nice and clear digital and analog layouts
- Quick reference text to help you compare with real-life examples
- "Keep Device Stay Awake" option for long duration recording
- Reset and clear current recording at any time
- Pause/Resume at any time

NOTES:

- Please do not expect a quiet room reading will be 0 dBA. The range 30 dBA - 130 dBA is the standard usable range and an average quiet room will be about 30 dBA.
- Although most devices are pre-calibrated, custom calibration is suggested for serious purposes requiring higher precision and accuracy. To calibrate, you will need a real external device or calibrated sound meter as a reference, then adjust the trimming value until the reading matches with the reference.

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New features

∿ Fix a an issue on Android 14 where after saving, app will not properly reset
∿ Components upgrade
∿ Various performance improvements and minor bug fixes

App Permissions

Allows an app to access approximate location.
Allows an app to access precise location.
Allows applications to open network sockets.
Allows applications to access information about networks.
Allows an application to record audio.
Allows an application to write to external storage.
Allows read only access to phone state, including the phone number of the device, current cellular network information, the status of any ongoing calls, and a list of any PhoneAccounts registered on the device.
Allows an application to read from external storage.
Required to be able to access the camera device.
Allows using PowerManager WakeLocks to keep processor from sleeping or screen from dimming.