Oh, the awful high frequency noise that our Intel laptop fans make. They just got to do that, don’t they? They want a small and fast computer at the same time, so what better way is there to do that than to place a CPU inside that generates a lot of heat, and spin a small fan fast to vent it out? Alas, the obvious penalty of this is the disposition to make high frequency noise, jarring noise as it is, but even more so when it is caused from moving air with turbulence.
Why do we use these monsters? Probably only because we are forced to for work. So, how do we comfort the ears with these? The most intuitive way is to simply find a way to direct the air flow away from your ears, to place a barrier between your head and the fan vents, to slow down the flow of air by spreading it out over a larger amount of space, and to find ways to absorb the high frequencies.
As it turns out, a simple way to do this is to design a foam padded cardboard structure that does just that. Direct the air stream away from your head by putting up barriers to point the air stream to the proper direction. This actually works pretty well.
For laptops, if you find your laptop is noisier in some rooms than others, take a look at the acoustic environment. Are there lots of hard, flat surfaces that reflect high frequency sounds rather than absorbing? Try padding out any such surfaces immediately within the vincity of your laptop. You’ll find it makes things a lot quieter.
Other interesting ideas, going above and beyond just the noise, the waste heat itself. In hot climates this can really make the environment too warm, so advanced fan ducting and venting measures can be taken to vent that hot air outside the room.
20191210/DuckDuckGo laptop muffler
20191210/https://www.overclockers.com/building-a-pc-muffler/
20191210/https://www.quora.com/Why-are-the-fan-vents-on-laptops-usually-located-on-the-bottom?share=1
20191210/https://hardforum.com/threads/my-pc-hot-air-exhaust-project-vent-hot-air-outside-the-room.1642510/