For full light coverage, we made a ring from FLORA NeoPixels. However if you want to do less soldering, pick up two NeoPixel rings and skip this step!
Lay a piece of wide tape on your work surface, sticky side up. Tape this piece to the table at the edges so it doesn't slide around or lift up!
Use tweezers to arrange six pixels in a circle, with the + sides towards the inside of the circle.
Strip a piece of wire and form it into a circle appropriately sized to match up with all the + pads on the pixels and solder in place.
Remove the ring from the tape.
Place the ring in the jaws of a pair of helping hands, and use small staple-shaped bits of wire to connect the data lines as outlined in the circuit diagram (outward facing arrows to inward facing arrows) in all the gaps except one.
To diffuse inside the earphone, the LEDs need to be spaced a small distance away from the outer plastic surface. Solder small lengths of wire sticking straight out from all the - pads on the pixels. Make them longer than you think you need, since you can always trim them later.
Use a long piece of wire in another circle to connect all the grounds (-) together. To reduce the possibility of shorts, we used an insulated wire that's had the insulation stripped just in the spots where the wire meets the pixel.
Solder the circle to the "posts."
Connect the seventh pixel in the center, soldering + to the center circle, - with an insulated wire to the outer ground ring, and the data input from the data output of the last unconnected pixel in the ring as shown.
One ring finished! Now make another just like it.