Personally as a trainer I think radios on a forklift are a horrible idea. Anything that distracts the vision or mind of an operator is not good. We have enough issues with drink holders, scanners and other stuff without that. Staying focused without a radio is not hard and not an issue, I farm some and spend hours on a tractor and can stay alert without it so operators can as well. Things like Howard Stern or news radio require active listening and could cause accidents due to inattention. Just my personal, non legal opinion.