Don't worry about that. Both interviewers that I emailed to thank did not respond at all, and I have heard from multiple people that their interviewers did not respond either. From what I hear it seems that they do not want to "mislead" you by sending you a response, so they just keep quiet. Persoanlly I think it's pretty lame because if someone sends me a thank you note I just respond with a your welcome type answer, out of a common courtesy, but again I am not deciding their admissions fate.
"No! Try not. Do. Or do not. There is no try.