THE GUINEA PIG EXPERIMENT
I read a study online where a scientist exposed guinea pigs to extremely loud music.  The results were that the guinea pigs who listened to extremely loud music continuously, say for 30 minutes, had severe structural damage to their internal ears. 

The guinea pigs who listened to the same extremely loud 30 minutes of music, but it was not continuous (roughly 2 minutes of music and then a 2 minute break), the damage to their internal ears was FAR LESS severe compared to the first group. 

Now remember, both groups listened to music the same total time (30 minutes).  But, continuous listening was far more damaging than intermittent listening.