The Acoustics Committee of the Hungarian Academy of Sciences among with other scientific bodies launched a project called Protect your ears! which aims to reduce early hearing loss in children. As a part of this project measurements were taken at several events held for children and it was found that in many cases the sound pressure level at these events exceeded the levels considered to be dangerous for the ears. These high sound pressure levels induce hearing loss in children which also makes it harder for them to focus on tasks. The responsibility to keep the volume of these events in check should fall to the organizers and the parents however the ears of many of them are already used to high volumes and thus they fail to notice it. The goal of this project, among other tasks is to create an easy-to-use method that provides accurate measurements of the sound pressure level at these events, allowing the parents to intervene and protect the hearing of their children. Nowadays most people use smartphones, the built-in microphone of which is able to produce accurate results of the sound pressure levels if properly calibrated. My task is to create an Android app which takes measurements, warns the user of potential threats to hearing in real-time, and sends these results to a server along with feedback from the users, where they are stored and processed.