Acoustic Signals (IMAGE) Curtin University Caption This shows acoustic signals recorded by the Integrated Marine Observing System sound recorder west of Rottnest Island (top) and by one of the hydrophones of the CTBTO's HA01 hydroacoustic station off Cape Leeuwin (bottom). Arrows show the arrival time at each station of the peak energy of the signal. Credit Curtin University Usage Restrictions None License Licensed content 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.