Check out this analogue ring by Etsy user Analogue Aesthetics.

analogue ring - pretty cool but a bit bulky perhaps (14mm height)…

The product page reads:

Sterling silver ring with built-in microphone that works! Crafted by hand, this version is the brushed finish look with a brushed perforated aluminum lid. Looks fantastic when used as a microphone or in standby mode as jewellery.

The ring comes in a US size 8 and a connection cable (3.5mm minijack) is included in the package so you can start recording right away. Price tag: $105 USD.

There’s a brushed version available as well.

Link via Boing Boing