Blue Tooth and Auto GPS

I have a voice command GPS (Garmin Nuvi 2597)
I drive a 36 passenger taxi cab and use the voice command when i need to find a location.
My problem is the noise level of the Bus.
I have tried using an Blue Tooth ear bud to hear and speak commands but have had no success.
Now the old software i used years ago (Delorme) and my laptop i was able to use wire connected ear buds and mic.
Is there a solution for my problem??