Social skills training is a type of psychotherapy that works to help people improve their social skills so they can become socially competent. SST is predominantly a behavioural therapy but cognitive therapy can also be used in some situations to maximise the success of SST.
Often a faulty toilet ballcock (fill valve) will cause resonance sounds like these. At least it's easy to check -- here's how to tell if this is the cause. Close the supply valves to all the toilets. If the noise disappears, open them one-by-one till the noise starts again. Replace the ballcock in that toilet.
How to determine what a toilet noise is and fix it. How to resolve the most common issues with your dual flush toilet. Solutions for a toilet that ghost flushes (toilet that turns on by itself) Solutions for a toilet fill valve that is slow or no longer fills the toilet tank.