how do install railsounds into a locomotive tender?

I have openend my tender and found that there are two emptey plugs by circet board.can i possibly get a chip for it to have railsounds and how much?
Thanks for any advice on the tender.Loco681

TrainsAmericaStudios and Digital Dynamics [Several others on here and myself are using Digital Dynamics, cheaper]. There is an OGR video that shows you how to upgrade and can be helpful.