The estimated hearing ability of German citizens is based on a comprehensive study published by von Stackelberg in 1986. At that time, 26.8% of West-Germany citizens were rated as hearing impaired. Because of the analyzing procedure used, these data cannot be used for comparison purposes with more recent international studies carried out e.g. by Uimonen et al. (1999), Wilson et al. (1999), Quaranta et al. (1996), and Johansson and Arlinger (2003). Other German data are based on non-representative evaluations or on subjective assessments. Therefore, the Institute of Hearing Technology and Audiology started H RSTAT, a two-year research project designed to fill this gap.