How can some people hear their own eyeballs move?

Question: How can some people hear their own eyeballs move?
- Keywords:
  eyeballs,
  human body
Asked by heatherjamieson to Ben, Jony, Katharine, Mark on 23 Nov 2011.
- Jony Hudson answered on 23 Nov 2011:
  
  Wow, I’d never heard of that – I’ve no idea how it would be possible!
- Mark Basham answered on 23 Nov 2011:
  
  Not a clue, If nothing else I certainly cant 🙂

Question: How can some people hear their own eyeballs move?