To obtain real-time, year-round acoustic data from the coastal Antarctic Ocean, an autonomous listening station, PALAOA (PerenniAL Acoustic Observatory in the Antarctic Ocean, or Hawaiian whale), was constructed in austral summer 2005/06, 15 km North of the German Neumayer Base. PALAOAs design was guided by demanding prerequisites: perennial, 365/24, autonomous operation, real-time data access, and full frequency and dynamic coverage. The station is located at 70°31S 8°13W, on the Ekström ice shelf, at 1.5 to 3 km distance to the ice shelf edge, with the Atlantic sector of the Southern Ocean to the North and Atka Bay to the East. Penetrating the ice shelf required boreholes of about 100 m length through solid ice, using hot water drill technology. Four boreholes provide access to the water for four hydrophones, lowered to about 70 m below the ice shelf bottom and 90 m above the sea-floor. PALAOA operates autonomously, powered by 8 solar panels, a Savonius wind generator, and a methanol fuel cell. The acoustic recording system covers the subsonic to ultrasound frequency range. Data are buffered locally and continuously transferred to Neumayer Base, from where a compressed, mono audio stream is transmitted in near real-time to the Alfred Wegener Institute, Germany. Beyond the goal of obtaining seasonal abundance data for marine mammals, PALAOA aims at determining the long-term noise budget for a pristine location as well as identifying and quantifying the various acoustic sources in coastal waters of the Weddell Sea.