The LokSound decoder will run on DC power, but you don’t have control over the sounds like you do when running DCC.
I always disable DC operation by reprogramming decoders that can run on DC, regardless of brand name, because my layout is DCC only.
I have read here that with some of the sound decoders you have to turn your DC power pack up to around 40-50 percent output before the locomotive will begin to move because of the extra voltage needed by the sound system.