If i understand your question correctly, you are trying to make all the objects that connect to your signal call a particular function.
one way to go about it is to pass the object that is emitting the signal along with the signal Eg. When you are calling the wave, you do something like this
# Wave Caller class
# new wave starting
# this is the single function that all connected object will call
then when an object connects to it, in the callback function, you do something like this
Another way to also go about it is using FuncRef, but i don't think that optimal in situations like this. I just hope this is what you are looking for