When non-elastic balls like a putty ball hit the ground they should waste their kinetic energy on heat and sound, much more than elastic balls. However putty balls hit the ground very quietly while elastic balls are much noisier.

So my question is how quiet can a bouncing ball be. Is it essentially noisy or are there materials which can be used to create quieter bouncing balls? Does it depend on it being hollow or the pressure of the air inside it?

There may be a complication as there is also a difference in the sound spectrum - maybe the sound of bouncing balls is simply concentrated in frequencies that are more annoying to the human ear. In that case my question another version with noisy meaning having a lot of energy around 4000Hz (the peak of the sensitivity of the human ear).

When non-elastic balls like a putty ball hit the ground they should waste their kinetic energy on heat and sound, much more than elastic balls. However putty balls hit the ground very quietly while elastic balls are much noisier.

So my question is how quiet can a bouncing ball be. Is it essentially noisy or are there materials which can be used to create quieter bouncing balls? Does it depend on it being hollow or the pressure of the air inside it?

There may be a complication as there is also a difference in the sound spectrum - maybe the sound of bouncing balls is simply concentrated in frequencies that are more annoying to the human ear. In that case my question another version with noisy meaning having a lot of energy around 4000Hz (the peak of the sensitivity of the human ear).

Edit:

I want to compare sound levels of bouncing balls of the same mass or at least of the same size, but with a minimal mass so that air drag won't slow them (so a balloon is not a candidate).

When non-elastic balls like a putty ball hit the ground they should waste their kinetic energy on heat and sound, much more than elastic balls. However putty balls hit the ground very quietly while elastic balls are much noisier.

So my question is how quiet can a bouncing ball be. Is it essentially noisy or are there materials which can be used to create quieter bouncing balls?

There may be a complication as there is also a difference in the sound spectrum - maybe the sound of bouncing balls is simply concentrated in frequencies that are more annoying to the human ear. In that case my question another version with noisy meaning having a lot of energy around 4000Hz (the peak of the sensitivity of the human ear).

When non-elastic balls like a putty ball hit the ground they should waste their kinetic energy on heat and sound, much more than elastic balls. However putty balls hit the ground very quietly while elastic balls are much noisier.

So my question is how quiet can a bouncing ball be. Is it essentially noisy or are there materials which can be used to create quieter bouncing balls? Does it depend on it being hollow or the pressure of the air inside it?

There may be a complication as there is also a difference in the sound spectrum - maybe the sound of bouncing balls is simply concentrated in frequencies that are more annoying to the human ear. In that case my question another version with noisy meaning having a lot of energy around 4000Hz (the peak of the sensitivity of the human ear).