There are over 175 million iPod users in the world today. Blasting your iPod or another portable music player has now been shown to cause temporary and possibly permanent hearing loss. Occupational noise exposure can lead to noise-induced hearing loss but less is known about the long term and short term effects of recreational noise. Here are some of the facts we’ve learned from the University of Colorado and the Children’s Hospital of Boston research: Many people assume there device has a maximum volume default setting that is safe. Current devices will produce noise up to 115 dB at maximum volume, the level of noise from a chainsaw or rock.