I have just invested a goodly sum of money for noise cancelling headphones except they are only good for listening to music. I wonder if anyone has invented a device for absolute silence so I can de-stimulate the stress of living in a noise infested city. I am constantly being irritated by music and repetitious noises that emanate from other peoples headphones. I used to go to the library for this reason but alas loud people and their devices have also destroyed the experience for me. I have asbergers syndrome an at times I envy the deaf. Is there a electronic soulution for me since I can easily live without music. I actually life the sound of the engine noises on the bus because it gives me something to think about but headphone noise and loud people really irritates me

Check construction or machine shop supply houses. Places where noise levels are high. They do make such headphones.

Here are some examples:
Earplugs + Hearing Protectors | Safety | Northern Tool + Equipment (http://www.northerntool.com/shop/tools/category_safety+hearing-protection)