Detection of astrophysical neutrinos at energies above 10^17 eV is of great interest since it would test cosmic ray production models and fundamental particle physics at 100 TeV centre of mass energy. Due to the very low predicted flux (less than ~0.03 km^2/year), other techniques beyond the optical are needed in order to instrument the 100 km^3 effective volume which would provide a few tens of events per year. The South Pole ice is the only medium in which optical, radio and acoustic detection methods could be used, allowing for the enhanced background rejection necessary to study GZK neutrinos. The South Pole acoustic test setup was installed as a R&D project within the IceCube experiment to study the acoustic properties of the ice and to investigate the feasibility of acoustic neutrino detection at the South Pole. Results will be presented concerning the measurement of noise level, impulsive transients, sound speed and attenuation length.