  The South Pole Acoustic Test Setup (SPATS) has been deployed to study the
feasibility of acoustic neutrino detection in Antarctic ice around the South
Pole. An array of four strings equipped with acoustic receivers and
transmitters, permanently installed in the upper 500 m of boreholes drilled for
the IceCube neutrino observatory, and a retrievable transmitter that can be
used in the water filled holes before the installation of the IceCube optical
strings are used to measure the ice acoustic properties. These include the
sound speed and its depth dependence, the attenuation length, the noise level,
and the rate and nature of transient background sources in the relevant
frequency range from 10 kHz to 100 kHz. SPATS is operating successfully since
January 2007 and has been able to either measure or constrain all parameters.
We present the latest results of SPATS and discuss their implications for
future acoustic neutrino detection activities in Antarctica.
