I worked for a several companies over the years that forbid radios in their vehicles. The reasons were simple, and completely centered on the machinery owners opinons. Just thought I would post those reasons as they do have a valid point.
Machinery wears out, even new stuff. If you catch a bearing when it first starts making a slight noise, and attend to it, you may save a shaft, or even a complete unit. Repair costs and down time can be reduced if the offending bearing is noticed early on. Operating a machine that costs as much as some of the tractors you guys own is a major responsibility so consider that when you turn up the volume or add earphones to your stereo to be used on the tractor. Plus also consider that other people may use your tractor from time to time and those funny noises that it makes may be hidden behind some of Lynyrd Skynyrd's best.
The incident that comes to mind was the twenty of so steel posts left in a FEL that one members wife accidently mowed with a bush hog and reported a strange noise coming from the mower. Just think if she had turned the radio on and didn't hear those noises, she might not have ever mentioned it to her hubby and he would have assumed someone stole his posts and left him a pile of scrap metal.
Point is, consider all the angles when you reach for the volume/on/off button, as there may be costs involved that are truly hidden costs, but since it is your equipment, use it as you deem proper.
David from jax