I prefer to wear a full face helmet(always) and earplugs(whenever highways are involved). If you are interested in either of those, then you should get to reading this post now. I always carry two sets of corded earplugs, because I can even lose corded sets on a roadtrip. I prefer Howard Leight FUS30-HP Corded. Those are a good price point for a good set of corded and mostly reusable/cleanable plugs with a case.
So I happened to be shopping at Mil-Spec Monkey, when I saw their take on corded earplugs; MSM Retracto-Plugs. Here's the video. I decided it was worth the $10 gamble to see if I could use them in a motorcycle helmet.
I was just a bit disappointed that the hook part of the hook-and-loop stick-on dots wouldn't grab the liner of my Arai helmet. So we had to use the sew eyes.
I pulled the cheek pads out of my helmet and found the deepest part of the ear relief to put it in. (If I had a do over I would point the string straight down instead of forward.)
I actually can pull the cloth off the foam to make sewing easier. My wife helped me out on this, but was a pretty simple affair. (Search youtube for sewing on a button.)
Here's what I got. The case doesn't hit my ears at all and I ride comfortably wearing or not wearing the earplugs. Of course, the plugs need to be fully out and installed in my ears before I put on the helmet. Also, I need to be careful to remove the plugs after I take my helmet off and getting the helmet too far from my head. The plugs retract and store nicely as advertised.
The extra bonus is the way the plugs attach to the cable via a threaded fitting. I can swap out the green ones../
for my usual when I need to.