Inspired by a comment from [spidermother] in the Audio File for Audiophiles idea: // There's a theory that our hearing is actually damaged by prolonged exposure to low band sound - i.e. sound lacking in the higher frequencies, including // ... // CD and most other digital recordings. The higher frequencies supposedly act like physical dithering, preventing, for instance, auditory cilia from getting stuck. // Many people worry a lot about kids getting hearing loss from listening to their iPODs so much, so I propose a simple product to fix this: Portable audio equipment designed to add high frequency noise. Clearly this wouldn't actually improve the sound quality, but for listening on the go, it probably won't decrease it much either. The obvious solution is to add this to the MP3 player, but then you need to have a good set of headphones that can reproduce the high frequencies. So I propose instead a set of headphones (probably of the ear bud variety) that capture some of the energy from the audible frequencies and use that to generate noise at frequencies too high to hear. These headphones can be sold as a specialty item to concerned parents (or anyone who believes it will help and wants to preserve their hearing) and can be used with any audio equipment. Users will of course have to crank up the volume a notch or two to keep the volume of the audible music at the same level as it was with normal headphones. The volume of the injected noise would be dependent on the volume of the audible sound for the practical reason that it would have to remove less energy from quieter sounds to prevent distorting the audible signal too much. A high-end model might even try to inject high frequency sounds that are harmonics of the sounds in the audible range.-- scad mientist, Apr 13 2012 [+] the "high end model" might even satisfy/fool audiophiles.-- FlyingToaster, Apr 13 2012 random, halfbakery