I've been wearing them for over a decade. Without them I only hear about 25% of what most people hear. I find they improved my quality of life a great deal. I do not wear them when cycling. It's not the wind noise that is the issue for me. Rather, it's the fact that they don't do well when drenched with sweat, and mine are behind the ear.
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A conclusion is the place where you got tired of thinking. - S. Wright
Favorite rides in the stable: Indy Fab CJ Ti - Colnago MXL - S-Works Roubaix - Habanero Team Issue - Jamis Eclipse carbon/831