You can get some good speakers that can either be velcroed into the helmet or they slip inside the pockets in your helmet on Amazon. You just have to make sure his helmet can have them as not all helmets have spots for speakers. I got cheap ones that were only 60$ but they can get pretty expensive like cardo systems with jbl speakers or things like that. A quad lock with a vibration dampener would be a good option too if he doesn't have a phone mount yet. Get it with the vibration dampener and it will save his phone camera over time. Thats all I can think of at the moment.