In-ear earbuds are everywhere, hell, I'm using them right now. But they're not ideal because they trigger a natural defense mechanism in your ears that tenses up your ear muscles and dampens the sound by as much as 50 dB.
These balloon-like earbuds don't trigger that reaction. How? Stephen Ambrose, the maker of these new earphones and pioneer of in-ear earbuds explains:
Ambrose's [new earbuds] employ a 2.5-micron thick polymer membrane, that functions by responding to changes in sound pressure level, "sacrificing" itself to save the eardrum. In place of the sealed canal, the lens creates an environment that, as Ambrose explains, "appears to the eardrum - and to the listener - as if it's open."
It's a fresh idea in introducing new in-ear earbuds that don't act like classic in-ear earbuds. Read the whole report on this new balloon style (and other styles) at Sound and Vision. [Sound and Vision via Pop Sci]