If your hearing a very strange sound coming from your roller skates and can't figure it out where it's coming from, then it is more likely you need new pivot cups for your hangers.
These pivot cups are for either Powerdyne Thrust or Tritonplates. These parts are meant to wear out over time and are super important to replace. Keep spares in your skate bag just in case.
At the World Of Wheelcraft skate shop in Sydney, we have a massive range of parts for roller skates.