One way to make it quieter is to put a bit of grease under the keycap -- that softens the sound that the spring makes when it buckles. However after a while th

One way to make it quieter is to put a bit of grease under the keycap -- that softens the sound that the spring makes when it buckles. However after a while the grease can leak down into the keyboard membrane. Another method is to put a piece of dental floss down inside each spring. Supposedly that reduces the sound quite a bit.