Foam plugs provide the best noise attenuation, but they can become uncomfortable on long rides. They are also a hassle to put in properly with the rolling and compression required of the foam for best performance. This is particularly true on group rides with many stops. In and out with the plug is a literal pain.
I use foam plugs on the track. New set for each session.
You can actually develop tinnitus from foam earplugs if they keep pushing earwax into the ear canal and cause buildup, and they put pressure on ear bones which is also a possible tinnitus risk.
I started using Bose active noise reduction earbuds. They are amazing, but not perfect.
The first in-ear noise cancelling headphones from Bose let you enjoy better sound every day, everywhere you go.
www.bose.com
Pros:
Very comfortable
Do not get inserted in ear canal
Provide sound attenuation almost as good as foam plugs.
Terrific when used with helmet communication such as sena or cardo.
Cons:
Cable management
Depending on helmet and windscreen, you can get a popping sound from windflow disturbances
Worth trying them as they are available for 30 day no risk return guaruntee.