So I have a late model Shokz and can tell you from experience: this "technology" is just hype and bullshit. It's just a speaker placed next to your ear, that's all. At best, what's left to be conducted through your skin and bones is just residual bass, maybe less than 5%. Plugged my ears with proper earplugs and played music in the Shokz. Nearly NOTHING is left, and I assure most of it is just normal sound still leaking through the earplugs, and appropriately muffed.
I don't know how no one ever tested or debunked this thing yet. I was first made aware of this possibility when I visited a Best Buy and tried on these eyeglasses (mind me, from Bose!) with tiny speakers attached. So, they don't purport to be "bone conduction" phones. They sound pretty much the same as my Shokz, it's the same experience.
Coming to think of it, how could it possibly work in the first place? Good sound is a lot more complex than just shockwaves.
My 2 cents.
Edit: I'm not saying the end result is unsatisfactory. I'm just saying it's not conducting any significant amount of sound through the puported means (bone conduction) and that's their entire claim to fame. Bone conduction. It's the deceitful nature of the purported technology itself that bothers me. Other than that, these headphones are good for the intended result - leave your ears free to outside noise.
Edit 2. Still not convinced? I have my Shokz on me now. If I slightly remove its contact with the skin, it should go silent, right? Well, it doesn't. Now try that with the screwdriver thing and see if you can hear anything.
Edit 3. Hey, look: all these "bone conduction" headphones have clear sound openings conveniently directed to you ear canals!
How good is bone conduction? - General IEM Discussion - The HEADPHONE Community
What are the best bone conduction headphones?
Bone conduction is just bullshit
Are bone conduction headphones any good
Can I use bone conduction headphones with tinnitus?
Tinnitus typically is a product of the brain in response to hearing loss. Bone conduction headphones won’t cure your tinnitus, but they’re safe to use.
Can I use bone conduction headphones with hearing aids?
This depends on the design of your hearing aid. If you have in-the-ear (ITE) or invisible (IIC) hearing aids, you should be able to use bone conduction headphones with hearing aids without issue. However, if you have behind-the-ear (BTE), receiver-in-canal (RIC), or open-fit hearing aids, you could experience some discomfort when wearing bone conduction headphones because they may make contact with the top part of the hearing aid module.
Standard headphones and earphones cause me BPPV (vertigo). Could bone conduction headphones be a good alternative for me?
Possibly! This is a difficult one to answer, but if what causes your vertigo is the seal over, or in your ear and the change in pressure that results, bone conduction does not seal anything. Therefore, it shouldn’t alter the pressure in your ears.
This is not a guarantee because we aren’t medical professionals. The canals of the ear are complex, as is the interplay with the ear’s connection to sinuses, and vertigo has a number of different causes. But, if it’s the change in air pressure that is your main culprit, have you tried open-back headphones, which generally have very little in the way of air pressure change by virtue of being open? Clamping force may also play a role, so perhaps an open-back headphone like the AKG K240, which tends to have a looser fit and is very much an open-back design, could also work.