  The next generation multi-cubic-kilometre water Cherenkov neutrino telescope
will be build in the Mediterranean Sea. This telescope, called KM3NeT, is
currently entering a first construction phase. The KM3NeT research
infrastructure will comprise 690 so-called Detection Units in its final design
which will be anchored to the sea bed and held upright by submerged floats. The
positions of these Detection Units, several hundred metres in length, and their
attached Optical Modules for the detection of Cherenkov light have to be
monitored continously to provide the telescope with its desired pointing
precision. A standard way to do this is the utilisation of an acoustic
positioning system using emitters at fixed positions and receivers distributed
along the Detection Units. The KM3NeT neutrino telescope comprises a
custom-made acoustic positioning system with newly designed emitters attached
to the anchors of the Detection Units and custom-designed receivers attached to
the Detection Units. This article describes an approach for a receiver and its
performance. The proposed Opto-Acoustical Modules combine the optical sensors
for the telescope with the acoustical sensors necessary for the positioning of
the module itself. This combination leads to a compact design suited for an
easy deployment of the numerous Detection Units. Furthermore, the instrumented
volume can be used for scientific analyses such as marine science and acoustic
particle detection.
