Don’t know the make of speaker that is fitted but the sound reproduction is excellent.
Where you source your decoder from, should have a video on their website to hear the loco sound, unless you are purchasing it 2nd hand.
As I am UK based and use Kadee couplers, Wheeltappersdccsound.co.uk have an uncouple function and Neil is a Irish railway modeller himself.
Roadsandrails, Murphy Models are suppliers as well and maybe Leggobiffoman ?
Other members will add info.