Hello I have two questions:   1st What would be the best way to test my headphone sound to see if they need to be returned? 2nd Would playing any these sounds (http://www.eminent-tech.com/music/multimediatest.html) on my headphones cause any damage to them? 

What Happened: The headphones that they own are the Sennheiser Momentums and today I let my friend try them on. However, because the headphones did not belong to him, he pressed them pretty hard against his ear (trying to listen to something). This in my opinion made the earpads holders very...