There is one other aspect to this which has been alluded to in other posts and that is largely behavioural.
Putting some sort of insulation under the appliances in the bedroom should make a difference, as would taking their shoes off when they come home. This may seem alien to some but it’s standard practice in Asian homes.
A mediation with your neighbours would allow you canvas the issues with them before you go down the road of legal action, and you can ask your strata committee to organise this for you.