Monster powerbeats sport ユーザーガイド

To avoid hearing damage, make sure that the volume on your music 

player is turned down before connecting your headphones. After 
placing headphones in your ears, gradually turn up the volume  
until you reach a comfortable listening level.

Noise levels are measured in decibels (dB), exposure to any noise  

at or above 85 dB can cause gradual hearing loss. 

Monitor your use; hearing loss is a function of loudness versus time. 

The louder it is, the less time you can be exposed to it. The softer  

it is, the more time you can listen to it. Refer to the chart* on the 

following page. 

This decibel (dB) table compares some common sounds and shows  

how they rank in potential harm to hearing.

1