i have tinnitus as well. it just suddenly occurred one day when i was working on my computer. no loud noises either. there are hundreds of causes of tinnitus and it can be very difficult to find the cause(s). in the case of loud noises like explosions or jet engines the tinnitus would have most likely started immediately or soon after the exposure. for teenagers and rockers long term exposure to loud music can do it but it can take years. viruses in the inner ear can do it (labyrinthitis) and i suspect this is the cause for me. tinnitus can rule your life if you let it but the first step is for you to see a good ent (one that specializes in inner ear problems) to see if you have one of the rare curable causes. most of the time the exam and diagnostic tests will only rule them out but not find the real cause. i have had my tinnitus for over 12 years now and i get by mostly knowing that there is little if anything that can be done to make it go away. personally i use masking noise (soft music or the drone of the television in the background) to fall asleep. during the day i just have learned to ignore it.
how long after working with loud noises can tinnitus appear. i worked with jet engines in the military and have developed tinnitus in the past years. i'm told it wasn't caused by military service but i have not worked with anything loud since.