OK guys, I need some technology help

The customer cannot hear the full bale alarm

Here is the configuration of the tractor.

No cab
No Muffler or at least it is ineffective
The full bale alarm is on the back side of the operators panel

I would like to put a microphone next to the full bale alarm speaker and mount an external speaker in a place where the operator can hear it. It needs to operator on 12v.or rechargeable batteries

So I need a microphone and speaker for a 12v or battery system. Suggestions?

Mike

OK guys, I need some technology help