Silent pressure coocker
It's really noisy when the pressure from a pressure cooker is released from the whistle at the top of the lid.
So if we use such a mechanism which lets the steam being released directly into top air thus reducing any kind of collision of steam with metal causing less noise. No worries about burning your face from the hot steam, because steam coming out of small hole at large pressure cools instantly as it comes to open space (pressure is negligible in comparison).
I even thought of a design using the simple mechanism of a jotter pen refill tom and the press button on the pen; which on pressing makes the refill rotate as it comes down so that it can be used for writing. So if we use the same sliding mechanism when the pressure from the cooker acts like the pen button that gets pressed and then when the slider goes to the topmost position a few small trough holes provided on the lid as well as slider will coincide and the pressure will be successfully and without much noise. Then the slider comes back to its original position with the help of spring.
No irritation of your ears as food is being cooked in your pressure cooker.
Reward: Just send me one such cooker so that i can sit in peace while my rice is being cooked!!!