"there is a guy waiving what look like two table tennis bats (I imagine that is not their proper name)"
Nicholas49. The extremly technical term term used is.........Bats or Wands
In reply to the original question. I some times have to do the headset on push backs. I sit in my van by the nose gear with my headset on and connected. Once all is closed up I wait till the crew call me and tell me they are ready for push. Mostly the call by voice but some times the use the ground crew call horn. The trick with this is to reply before they take their finger off the button!!!!
It makes them jump.
Rgds Dr I