Acoustic Cloak (2 of 2) (image) Duke University Caption This is a close-up view of the 3-D acoustic cloak. The geometry of the plastic sheets and placement of the holes interacts with sound waves to make it appear as if it isn't there. Credit Duke University Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.