When I use pressure cooker, hissing sounds are produced and vapour comes out of the vent pipe.
To a certain extent, noise is unavoidable.
The pressure cooker must be able to vent, to avoid building up too much pressure. It vents through a small hole so it can build up some pressure, this is what makes a pressure cooker work (high pressure means a higher temperature).
If the vent gets larger, you'll get less noise but the pan won't be able to build pressure any more, making it pointless to use one instead of a normal pan.