It is? How much ground to cover per person? Just curious. (Because, as someone who is somewhat spatial-awarenessly-challenged, a thousand people per square foot doesn’t sound like a whole lotta personal space to me.)
That’s a thousand people per square mile (mi2), not per square foot.
1 square mile is a square 1 mile on each side.
The square root of 1,000 people is 32 (rounded up).
Each person would have a personal square of approximately 1/32 of a mile on each side, or a square around 165 feet on each side.
Mile! I meant mile!
That being said, 165 square feet per person (averaged out) doesn’t sound so bad at all.
I guess if one really wanted to average out the average “personal space” available in a nation, you’d have to subtract things like roads and the space needed to farm that person’s food etc.
I dunno, it seems like you can’t swing a (man-made, stuffed plush) cat around here without 3 or 4 folks getting hit.
(bolding mine)
‘P.C. police’ peeking over your shoulder? 
It’s not 165 square feet per person, it’s 165 feet squared (a square with 165 feet on each side.) That’s 27,225 square feet per person.
Back to the OP
If it were possible, the only way I could see would be through a change in air temperature due to pressure change. However I’m pretty sure that the process is slow enough that as heat collects above India it would be a diabatic process with the rest of the atmosphere.
Only if you can get a small shirker named JoJo to yell “Yopp!”
They’d have to all yell “We are here!” for someone besides Horton to hear them.
Actually, this very event happened last Thursday. It was deemed a failure because one guy in Bangalore thought it was supposed to be the *next *day and didn’t shout. The ISS crew was divided; several thought they heard a weak shout, while the rest claimed it was just somebody passing gas.
But what if all the Indians in North America did a Mexican wave?
I can’t believe there is no xkcd strip about this.
ETA: Missed the earlier cite.
What if their government first spent ten years giving everyone vocal lessons so when they screamed, they’d all be exactly on pitch? Would constructive interference help?
Can they use a radio? One tuned into Delhi’s most popular station? Because that’d be pretty easy.
Simple: look at the webfeed that is synching the event and livestreaming so the rest of the world can participate, and see when everyone is shouting.
And if they heard it, they could nuke them from orbit, but only if they were sure.
Cecil didn’t even try.
Muricans making fun of us Indians!
Wait till we gang up with the Chinese and expel flatus in a globally synchronised event. 
Save that until we need to dodge an asteroid.