Very, very silent: http://64.233.183.104/search?q=cach...ans_under_25dba.html+25dba&hl=en&ct=clnk&cd=1
Decibel Level (dB) Source 140 threshold of pain: gunshot, siren at 100 feet 135 jet take off, amplified music 120 chain saw, jack hammer, snowmobile 100 tractor, farm equipment, power saw 90 OSHA limit - hearing damage if excessive exposure to noise levels above 90 dB 85 inside acoustically insulated tractor cab 75 average radio, vacuum cleaner 60 normal conversation 45 rustling leaves, soft music 30 whisper 15 threshold of hearing 0 acute threshold of hearing - weakest sound