Have you ever know how loudly you speak and measure you noise or how much volume you need to hear clearly while watching television. A free small Android app can help you to measure the noise with the help of your android phone. Download sound meter app from android market and launch the app. Now your Android phone act as a sound meter and measures the least, mean, and maximum ambient sound levels of the environmental noise in decibels (dB). You can see the typical noise levels of everyday sounds in the image so you can get an idea of what those sound levels represent.
Acoustic meter uses your Android smart phone’s mic to measure noise volume, so depending on your phone’s hardware, which has been aligned to human voice(300-3400Hz) and not required high performance. So the hardware maximum values are limited and you may not be able to get the top end of the scale, but still useful.