iPhone Music: How loud can you go without damaging your hearing?

[HarryPot]

I've aways wondered how loud can you put your music in your iPhone (iPad) without harming your hearing.

I know depending on dB and the time you hear the music it is how you can measure if any damage might be done. But, is there any measure of dB using standard headphones in your iPhone?

Since buying noise-cancelling headphones I rarely go above 50% of the slider, not sure how loud is this for hearing music more than an hour.

 

[LaWally]

There are tons of articles on the net about iPods and hearing loss using earbuds, which would also apply to iPhone and iPad users. Here is a snippet from one article:

"Cory Portnuff, an audiologist at Colorado has documented that listening to earbuds, or in-ear headphones, for 90 minutes a day at 80% volume is probably safe for long-term hearing — a useful cutoff point to keep in mind. But softer is better: you can safely tune in at 70% volume for about 4½ hours a day."

here is a link to the whole article:
http://www.time.com/time/health/article/0,8599,1881130,00.html

Extrapolating these numbers would suggest no problems at 50% volume for 12 hours a day.