You are correct but you forgot the distance term in the equation! We do not hear the GPA jets taking off. I do not hear my neighbors dishwasher.From the interweb.
Note that yard equipment has a higher DB level than a motorcycle.
The noise chart below lists average decibel levels for everyday sounds around you.
150 dB = fireworks at 3 feet
140 dB = firearms, jet engine
130 dB = jackhammer
120 dB = jet plane takeoff, siren
110 dB = maximum output of some MP3 players, model airplane, chain saw
106 dB = gas lawn mower, snowblower
100 dB = hand drill, pneumatic drill
90 dB = subway, passing motorcycle
80–90 dB = blow-dryer, kitchen blender, food processor
70 dB = busy traffic, vacuum cleaner, alarm clock
60 dB = typical conversation, dishwasher, clothes dryer
50 dB = moderate rainfall
40 dB = quiet room
Noise intensity or sound pressure is function of the distance from the source and the number of sources.
It obeys the equation of 1/R where R=distance. As distance increases the noise decreases is significant.
Few lawn mower operators have reason to operate more than one lawn mower or pieces of lawn service equipment concurrently.
But, there could be more than one dirt bike or ATVs operating concurrently in the ATV Noisedome and for longer times.
Electricl power measure for consumption in Watt-Hours, dB must be quantified in dB-hours. You will quickly determine that the ATV dB-hours will significantly exceed the dB-hours of all of the above.
I am a physics major drop out.