之所以有些人带小耳塞和入耳式,导致听力下降 ---this is dangerous enough. 即使是开放的大耳机,开大音量,也会造成这种后果。 -- true, do not use head phone too much. whatever brand or design. one of my friends use 580 and 600 too much and finally told me that it is a mistake. i just do want other people to have the same bad luck. it is true that if you make sure 1000 things are right, headphone might be okay. but can you always makes sure the 1000 things are always right?