Thx for the reply, but I am not an engineer and do not have the necessary skills or equipment to do this.
I am a simple consumer with good ears.
Today I got an email as an answer to my question of a silent keyboard to a manufacturer of keyboards. He admits explicitly, that it is the electric circuit of LED, that are responsible for the noise. They do know it, but can't do much about it, because of the marketsituation. The keyboard would cost much more and according to their financial-analysts, it will not add up to produce such high quality keyboards, because the revenue would not be enough.
We also had a phone call on this. Jokingly said, pay 5k to 10k € and you may get a keyboard, that fits your requirement, because of development and manufacturing cost individually.
The majority of people want trash, they get it.
So, that's it, simply as it is.
Year, we are just talking about unwanted noise of devices, that are not supposed to make any noise. A pure input device like a keyboard or a mouse and a pure optical device such as a monitor. They should not emit any noise! But most people are either plain deaf, dumb or ignorant about this. Just imagine how animals, like cats and dog may feel around such noisy devices. But hey, we don't care. We' re just dumb enough to ignore and become deaf, because we just love to have fun, right? What a stupid creation our species actually is... we can fly to mars, work on nuclear fusion, engineering nanometer CPUs, making high precision measurements up to fractions of the diameter of elementary particles detecting gravitational waves - but we still can not produce silent input devices... if this is not sad, what else is?
Honestly - we suck!
If I would be a millionaire or billioniare, I would go for it, just to see to make it happen.
No matter the cost! If it costs 10k, 100k or even 1.000k € or more to make such a keyboard. I want to see those engineers and those financial analysts squiggle around. Yes! It is possible! Just do it!