This is somewhat similar to the situation in a "vacuum cannon" - one of those research/demonstration devices where they accelerate light objects like ping pong balls or meteorite models to very high speeds, way past mach 1, by
The problem is, there's always extra noise involved with those, like breaking the diaphragms and the thing they're firing hitting stuff.
My guess here is that it would be very noticeable but not very damaging=there would be a sudden wind towards the hole and a drop in pressure that would really thump your eardrums, but any kind of sonic wave from the air colliding in the middle of the hole would be almost nothing because its surrounded by a much bigger shell of rarified air, blowing directly towards it. Even if you were right at the boundary when it disappeared, I can't see it would be any different than a very very hard gust of wind.
I can't see how there could be any supersonic effects or any overpressures over 1 bar, outside a spherical void, because all the energy and air involved in the middle would have to reduce the pressure and total energy outside the void... which geometrically is going to be bigger (although that effect obviously goes away the bigger the void is, until at some huge size you could pretend the boundry was a flat plane i guess)
Now if the area that suddeny becomes vacuum had some interesting shapes, I think you could produce weird jet effects by changing the shape, but i still dont see how you can transfer much energy outside the area if the entire area disappears at one time. Those vacuum cannons work by breaking the membranes at different times.
TLDR: i think people right at the boundary would get blasted off their feet by wind or smashed by cars or buildings blowing onto them. They wouldn't have permanent hearing damage or even burst eardrums, but they'd all go OW what was that whomp noise. They would all get really cold really fast but very briefly, and there might be a wave of sudden white mist that went away in seconds.
people standing around 2 radiuses or more from the center of the void would probably just feel a strong gust of wind and hear a huge WHOMP noise, and 3 or 4 radiuses people would just hear a weird echoey whomp.
super short still TL still DR: I think it would be pretty underwhelming, there's a lot less kinetic energy involved than a small bomb or something, and less transmission of it.