News Earbuds with solid-state audio drivers are about to go mainstream

[AC News]

Most earbuds have regular dynamic drivers, but solid-state audio drivers that use silicon are about to gain momentum.

Earbuds with solid-state audio drivers are about to go mainstream : Read more

 

[Navanski]

Is this not just a new reiteration of the piezo electric driver that Sennheiser used in a couple of headphone models in the late 70s?
I had a pair of Sennheiser K145 from that era. The manufacturer called them electrostatic but that description seems a little dubious.
I remember that the upper registers on those headphones were ultra fast and they sounded better than my mates more expensive Koss Pro 4AA.