Earbuds and earphones are not the same.
Earphones penetrate the ear canal. Earbuds ( ala Apple stock ones ) do not.
Both supply sound, earphones are very different.
I hear what I need to hear from the outside world perfectly well while listening to audio books through my in-ear earphones, which also cancel out the noise from wind turbulence.
Exactly....you need to attenuate outside sounds ....mainly wind noise....it does not mean you cannot hear other outside sounds. Your ears shut down if they are overloaded by wind noise and regain sensitivity when it's quieted by attenuating earphones or earplugs.
Earbuds do not attenuate as they do not seal to the ear canal - something required for both good sound and ear protection.
If you listen to loud music then that drowns outside sounds ....no different than in a car.
Some of these people making stupid laws should really get some physics/audio lessons.
In helmet speakers do nothing for protecting your hearing, are often shrill and lousy on music.
With the SENA 20s now allowing plug in earphones helmet speakers are a complete was of time.
I used to use them in addition to the earphones when I had no choice.
You can have a normal conversation with attentuating earphones tho you won't hear lw voices or whispers., just as you could not if you were further away.....that is exactly the principal.