I agree, lol i need to buy some air cleaner. But is it possible that noise could be cause by another issue, cause i dont think processor heat is the issue, as it seems cool enough
To clean
What I do is this: keep the PC plugged into the wall socket but powered off. It is earthed. Get a vacuum cleaner that hasn't been running and "earth" the plastic hose by touching some grounded metal object. Get the vacuum cleaner in position.
Turn on and vacuum, holding your hand between the PC and the plastic nozzle. DONT let the plastic nozzle touch any of the PC components just in case there has been a static build up. There is at least 5cm between the end of the nozzle and the PC components. Your hand forms a brace to stop it getting closer.
Don't take your time over it. Be swift. Don't race... but also dont take forever and risk static build up. Turn off vacuum cleaner.
It has worked for me fine, no problems, for last 10 years. No, it isnt recommended, but yes, do it carefully, and you should be fine.
Ageing components
Unfortunately, sometimes PSU's or voltage regulators on mainboard or GPU age and fail over time. I had this with a Pentium 3 laptop... the solid capacitors they used around the CPU were underspecced, voltage instability, CPU shut down. On desktops this can cause the emergency music you hear. But doesnt have to be the CPU, could be the PSU, chipset or GPU as the root cause. To check: try pulling the GPU. Also try swapping the PSU.
[disclaimer]at your own risk, no warranties or liability accepted[/disclaimer]