• Panasonic's upcoming RP-HJE900 headphones has a little zirconia on the inside for sound quality,
  
• The "fake diamond" crystals are good for conducting sound, and are used to lower distortion.
  
• the resulting headphones have a sensitivity of around 100dB/mW and a frequency response from 6Hz all the way to 28kHz.
  
• The design is pretty simple earbud-shaped, but features removable/replaceable cables— a feature usually found on very high-end models.
  
• No info on pricing, but they'll be available from June 15th