Let’s say I’m in Princeton, NJ and say something at “normal” volume level, about 65-70 dB. How much better hearing than the average person possesses would be needed for someone to hear what I said in, say, Tokyo, Japan? I’m outside in my hypothetical scenario, so don’t worry about mundane an unimportant things like the walls of my house reducing the projection of my voice.
No matter how sensitive ears (or a microphone, or whatever) might be, they would not have the remotest chance of hearing what you said at that sort of distance. That far away (indeed, even much less than that far away), any effect upon the motions of air molecules in Tokyo that might theoretically be traceable back to the effect of your voice would be far smaller than, and so completely swamped by, the random thermal motions of those molecules; and that is not even taking account of all the other sources of sound between Princeton and Tokyo that would also be drowning out your voice.
Well, on a clear day, how far does 194 dB travel? (That being the loudest sound the atmosphere will hold.)
The 1883 eruption of Krakatoa was heard up to 3,000 miles away (described as cannon fire), which is roughly the furthest east-west distance across the continental U.S., but far short of crossing the Pacific (e.g. 4,776 miles from Seattle to Tokyo).
Looking at the link in the second post from this thread, 194 is only **mostly **there…
Not arguing; just wondering where you got that number.
It is based on the largest possible pressure wave that the atmosphere can sustain; 194 dB produces a wave that is +/- one atmosphere peak, and you can’t go lower than a vacuum, so that is the highest undistorted sound wave you can generate (the number and calculation can be found all over the 'Net, such as this example):
Loudest sound = 20log(101325 Pa / 2x10^-5 Pa), where 101325 Pa is the standard atmospheric pressure at sea level (thus the loudest sound will be lower at elevation, or a bit higher if under a high pressure area)
Naturally, it is possible to generate even louder sounds, but it will be distorted on the negative pressure peak, so you technically no longer have full sound waves, more like a shock wave, which has a rapid rise in pressure but little or no negative amplitude (shock waves don’t propagate as well though).
So how far can this “loudest sound” travel in undisturbed atmosphere at ground level pressure? I’m assuming Krakatoa was a shock wave? I’m looking for pitch, baby!