(btw: I don't use ear buds as they don't create the seal/hearing protection of custom molded ear plugs (or even foam ear plugs).)
For you perhaps. I don't use custom molded ear plugs because they did not create the seal/hearing protection that my ER-6 earbuds do.
Different strokes for different folks, I guess.
My experiences, and obviously YMMV:
Custom molded earbud speakers: DO NOT get Westones. They are a hard vinyl material or such and are more painful and do not seal as well as the softer silicon that Precision Labs uses. Just about all of them out there use precision labs, including bounce's source. Various vendors may do the fitting, but the molds are sent to either Precision Lab or Westone to have them made. Like I said, make sure you go with Precision Lab. Cheaper and better IMHO. And when it comes to motorcycle custom earbuds, Precision Labs make a bunch more than Westone. Like a 10 to 1 ratio. More than likely a reason for that.
After saying all that, custom molded earbuds did not work for me. And I went back to an audiologist several times to have them remade. They just did not seal for me.
I ended up going with Etymotic ER-6 earbud speakers. I use them with the silicon rubber covers. You can also use foam. I have never tried the foam as the rubber works for me.
Excellent noise attenuation. Great sound. Shop around, and you can frequently find them for $100 or so. Still, depending on what helmet I wear, comfort can be a factor. (Also had the same issue with the custom molded earbuds) If the side of the helmet is pressing at all on my ears, I will eventually get discomfort. Also the cords can be a PITA, and if you mistakenly tug on one not only does it h urt, but can unseal the earbud.
It is for some of those reasons, I plan on installing speakers in one of my helmets. I will still use the ER-6s, but I also want the option of having speakers in the helmet. Of course I will wear foam earplugs with helmet speakers, so sound quality may be degraded a bit, but that is not a factor for me. I know there can be issues with helmet speakers, but I want to give them a try. I want the flexibility of using either helmet speakers, or the er-6s.
As for hearing protection, I can't see any difference between proper sealing earbud speakers, whether custom or not, and helmet speakers used with good ear plugs. Both attenuate the bulk of noise, and allow you to vary the volume of what you want to hear.
Cripes! This is becoming a "dreaded" thread!