"It is the energy flow via the electrons that creates the audio signal. While the actual speed of the electrons themselves is slow and their movement is characterized by more than one form of movement, the sound we hear actually travels very fast via the energy flow through the electrons."
Actually, energy doesn't flow thru electrons, electric charge does. Rate of this electric charge is measured in Coulombs per second and called electric current. Energy travels on the outside of the cable thru magnetic field (called the Poynting field). For instance, electric charge flows from one terminal of battery thru the load to come back to another terminal while energy flows from both terminals to the load on the outside of the cable.
This might help: http://amasci.com/elect/poynt/poynt.html
Actually, energy doesn't flow thru electrons, electric charge does. Rate of this electric charge is measured in Coulombs per second and called electric current. Energy travels on the outside of the cable thru magnetic field (called the Poynting field). For instance, electric charge flows from one terminal of battery thru the load to come back to another terminal while energy flows from both terminals to the load on the outside of the cable.
This might help: http://amasci.com/elect/poynt/poynt.html