Back in the 80s and 90s, I used a 2-meter handheld radio while riding my motorcycle…
The radio sat in the tank bag. The PTT button was mounted on the handlebars, while the microphone and earpiece were installed inside the helmet. The cables were chosen to be thin enough to snap off in the event of a crash. The connection to PTT .. and the helmet was a 3.5mm jack that tucked away between the padding and the shell. It worked quite well… especially for bike-to-bike communication while on the road (which was exactly what it was designed for).
73 Armin