Hey Ron,
Now that you brought it up, there are a multitude of possibilities for having a bluetooth connection in an engine. I like your idea. As long as the dummy has a power pick up or a battery to supply enough power to drive the speaker(s), it would certainly enhance our train's sound systems. Imagine having pusher dummies with sound at the end of the train; no fear of pushing the train off of the tracks. How about nice big blue tooth sub-woofer under the layout to add some bass and a "whole room" sound to our operations.
My grandson and I each have Kato Sound Box systems for our N scale trains. It takes away the toy like sound and fills the room with really good sound. Adding a cheap set of computer speakers makes it even better. We could have some of that in our O guage trains with a blue tooth connection.
I hope someone from Lionel or other company picks up on the idea.
Thanks and have a Blessed Christmas
Earl