IIRC, you can listen to music through headphones or ear buds if you want (as long as you aren’t communicating with people outside of the field). I would double check with your EP or the refs about it before you compete.
I would also make sure you leave the volume low enough so you can still talk with your alliance partners midmatch. But it’s totally understandable to need music playing to get focused.
I don’t think I would be able to find the post in reference, but I think it being stated that it would be fine to use wired earbuds as long as you only had 1 in (so you could still hear the referee’s calls).
On the other hand, why not try a teammate? You get three people in the drive booth, You drive, another guy communicates with your alliance, and the third guy becomes your personal radio.
As a coach/mentor, my take is this. If you are standing at the field as part of the drive team, you should have a role to play at the field. You are either driving, co-driving or you are coaching the driver/drivers. Otherwise, what is your purpose being there? And if you have a role, you wold need to hear and be heard. So having ear buds in might make it difficult to do that. Each team is different, so your team can do as they choose. But my opinion is that you should only be at the field if you have an actual active role to play, If you are just spectating, there are usually stands for that.
Our driver used to do this actually. Just keep the music low and keep only one headphone in. Idk if it’s ok according to official rules, but we were never told that we couldn’t do it. At the very least, it’s okay for regionals
Music is a distraction and can even tune out your teammates that need your help during the match. Plus in the heat of the moment you should not listen to music unless you plan to lose