Disable the LG washer/dryer melody at end of the cycle?
I've used the following method to make obnoxious sounds coming from home appliances and toys much quieter:


Find where the sound comes from. Usually there's a little grill or perforated plastic that covers the loudspeaker or piezo inducer.
Tape over it with a transparent office tape. I sometimes do two layers in cross-hatch pattern if sounds are very loud.


Usually, it makes the sound quiet enough not to be bothersome anymore. You could, of course, disassemble the whole thing and cut the wires to the speaker (if it's not PCB-mounted, which many of them are), but in my experience just covering the hole where sounds come from is good enough.