Reference

Sound Thinking

Source	Level, dBA
Military Jet at 100ft	140
Artillery Fire at 10 ft	130
Passengers Ramp at Jet Airliner	120
Discotheque	110
Textile Mill	105
Printing Plant	100
Platform of Subway Station	100
Jackhammer, 15 meter	97
Generator Room	90
Unmuffled Diesel Engine at 130 ft	90
Heavy Truck, 15 meter	85
Concrete Mixer, 15 meter	80
Computer Printout Room	80
Inside Auto, 64km/hr	76
Vacuum Cleaner, 3 meter	70
Freight Train at 100 ft	70
Auto, Pass by, 30 meter	65
Conversational Speech at 3 ft	60
Large Transformer, 15 meter	58
Urban Area	55
Window Air Conditioner	50
Suburban Area	45
Quiet Country Setting	35
Soft Whisper, 2 meter	35
Empty Broadcast Studio	28
North Rim, Grand Canyon	25
Threshold of Good Hearing	10
Threshold of Excellent Hearing – Youth	0