The power generation of a wind turbine is determined, among other things, by its hub height. In recent years, a new, effi-cient and economical design for high wind turbine towers called hybrid towers is developed consisting of two sections. The lower section consists of prefabricated concrete ring segments that are post-tensioned together and assembled at the tur-bines site, whereas the connected upper section is composed of conventional steel rings. The prestressed tendons in the lower section are located inside the tower and ensure the stability of the wind turbine. Thus, these are critical elements and any damage to them should be detected as early as possible. The tendons are often highly prestressed and exposed to high dynamic loads. Fatigue failure in the prestressing steel is a potential risk. As the tendons are covered in plastic pipes and in some sections have contact to the concrete segments the access is limited for inspections. The aim of the presented inves-tigations is the development of a monitoring approach for the immediate detection of the occurring wire breaks. Acoustic emission measurement has been proved to be a promising technique for that and thus should be assessed. For experiments tendons were prestressed in a test frame with the dimensions of 12 x 4.1 m analogous to the boundary conditions of a real wind turbine. Wire breaks as well as wire break-like signals were generated on tendons, which are recorded by piezoelectric sensors and analyzed by a measuring device. The results show that by acoustic emission measurement the wire break signals can be well recorded. The results from the large-scale experiments are transferred towards the application at real structures.