This is a simple decibel meter for measuring audio levels.
The app provides a simple way to measure audio volumes in your environment. The app shows the approximate dB (decibel) level, also known as Sound Pressure Level (SPL). This app is mainly intended for fun, educational purposes, not for professional-level volume measurements, for which you should buy an actual SPL meter from your local electronics store.
To adjust the calibration, tap the "Configure" button, and then adjust the value based on whether you are using an internal microphone (iPhone users) or an external microphone (iPod Touch users).
Please note that this application requires an external microphone for use with the iPod Touch.