Thunder is rated at approximately 120 decibels, according to www.lhh.org/noise/decibel.htm. I can remember hearing thunder, though, with a sudden "crack" quality that hurt my ears big-time, so I guess there must be a fairly wide range in the decibel level. In comparison, a chainsaw is rated at 125. a car horn at 110, and 170 for a shotgun. A handgun is rated at 166, and I can personally attest to the fact that if you are within one or two feet of a Smith and Wesson .38 caliber handgun when it's fired, and aren't wearing some kind of hearing protection, your ears will ring to the point where you won't be able to hear anything afterwards for a good 20 minutes, if not longer. (It will also throw your balance off) That made the thunder crack cited above sound like a gentle breeze. Another source says that 160 db is the level for "instant perforation of eardrums." Since both my ears still work, it seems like a good idea to take any and all of these with the proverbial grain. http://www.glenbrook.k12.il.us/gbssci/phys/Class/sound/u11l2b.html Some other common man-made noise levels (approximate): • 10 normal breathing • 20 whispering at 5 feet • 30 soft whisper • 40 quiet residential area • 50 refrigerator • 50 - 75 washing machine • 50 - 75 air conditioner • 50 - 80 electric shaver • 55 - 70 dishwasher • 60 normal conversation • 65 - 80 alarm clock • 70 TV audio • 70 - 80 coffee grinder • 70 - 95 garbage disposal • 75 - 85 flush toilet • 80 pop-up toaster • 80 ringing telephone • 80 - 90 blender • 80 - 95 garbage disposal • 110 shouting in ear • 110 baby crying • 120 ambulance siren • 140 airplane taking off • 143 bicycle horn • 150 jet engine at take off • 150 firecracker