Desktop computer control fan sounds

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It depends on the Fan itself, if the Fan is >30 dBA then yep you need a controller <or> use Fan_Headers that offer fan speed control on the MOBO itself and controlled by the BIOS.

Fan Controllers - http://www.newegg.com/Product/Productcompare.aspx?Submit=ENE&N=100007585&IsNodeId=1&bop=And&ActiveSearchResult=True&CompareItemList=11%7C11-992-005%5E11-992-005-TS%2C11-998-808%5E11-998-808-02%23%2C11-992-004%5E11-992-004-11%23%2C11-998-065%5E11-998-065-TS%2C11-998-055%5E11-998-055-03%23

As far as the CPU, typically by default on 4-pin CPU Fans in the BIOS there's settings to control fan speed per temperature; most of the time Load (Optimized) Defaults accomplishes this control. IF the HSF is 3-pin then often you can either choose 'chokes' normally included with the kit or use a Fan Controller with temperature control and program the fan speed levels.

Q - What HSF?
Q - What MOBO?