You are downloading the Decibel Meter XAP file v18.104.22.168 for Windows Phone. Decibel Meter is a free and useful Productivity app: Gives real time readings of the decibel level of the surrounding environment as detect by the devices microphone. ... You can now download the offline XAP file to install & try it.
Download Locations for Decibel Meter 22.214.171.124 XAP file
Note: To install it manually from an SD card, you should choose one of the server location above to get the offline Decibel Meter XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.