This is one of those things where you don't really notice until someone says something. It's for our own good, for me to point this out to the community. I believe it will evolve Playstation even further.
Similar to how obnoxious a loud mouse or keyboard is in a quiet room. That loud consistant clicking, as if it were an endless torture to those trying to sleep. I was playing last night and realized just how loud the PS4 (or any controller for that matter) is. The triggers squeak and click, along with the square, triangle, circle, and X buttons, as do the analog sticks. similar plastic on plastic.
Now, for my proposition, we are becoming aware of the faulty rubber used on the Analog sticks. As comfortable as it is the material deteriarates innapropriately, and prematurely. When that is eventually corrected, the new rubber material should cover both the thumb pads of the Analog sticks, down the plastic stick which they rest upon, This rubber layer on the stick will help prevent that loud clicking the Analog stick's plastic on plastic emits. Silencing the noise created from pushing the Analog sticks in for your R3 and L3, as well as the noise from the 4 triggers, will take some tinkering.
I also noticed how brilliantly the D-pad sounds in comparison to all the other buttons on the controller. It even feels like a much softer type of plastic material, allowing a smooth collaboration between the two plastic materials. Which emit a comfortable and subtle sound instead of a loud obnoxious un preventable click the other buttons create. Using the D-pad material (or perhaps something else) could help cut down the loud clicks the other buttons make. (Although remember, the buttons remaining seperate and not on one track, like the D-pad, is essential).
Thank you for you time, and please consider this, if not for me for the community and future development of Sony Computer Entertainment.. If you wish to speak with me further on the subject, I will gladly contribute; just send me a message.