You have to tell us more facts.
The minimum is exactly which Mint you have - which version and which edition
(main or any of the CEs)
We also need to know a bit about all your hardware.
Run " lspci " in a terminal and post here
Also run lspci -vvnn and post the section for your "problem", but only that section please
Some wifi and possibly built in sound can be connected to USB even if they are internal - if you suspect you have one of these run " lsusb " in a terminal.
contains links to all (?) the really good solutions for sound in Mint
Also tell us if this is using mint4win or not, quite important
This is a standard answer so it may not be fully applicable to your situation