Measuring noise with your phone

Decibel X is an app for the iPhone ($3.99 per month, also available on Android) that is a noise meter. It pretty accurately measures noise on a decibel scale. I use it to monitor the noise levels in restaurants and workplaces in an effort to increase quiet. When I am recording podcasts I use it to ensure there’s little background noise. It’s also entertaining and instructive to measure sound levels outside in nature and urban areas. — KK