Can listening to loud music really cause hearing loss?

Yes: Any persistent loud noises more than 80 db can cause damage to the hair cells of the cochlea and thus cause hearing loss.

Absolutely: It depends on two variables. The intensity of the noise (greater than 85 decibels) and the duration of exposure. If you are exposed to loud music for at least 8 hours a days and if the loudness is great enough, you will develop NIHL, (noise induced hearing loss). And this is a permanent high frequency hearing loss.