Is it possible to measure decibels when listening to music on a headphone / MP3 player?
Yes. Most police carry such a device to enforce loud noise bands in many municipalities. Radio Shack (for one) sells a consumer version as well as most musical instrument stores. They are mostly just a microphone connected to an amp that has a meter or bar graph type display that is calibrated in sound pressure in db’s. They need only to be pointed at the sound source to get a reading. If you held it up to your ear phones, you could measure the actual pressure being presented to your ears at any given volume level. Since the advent of portable sound devices, even before the I-pod, many young people have been damaging their hearing. If some one is walking by and you can hear the sound coming from their earphones, they are damaging their hearing. The sound is to loud!!!.
