In accurate and repeatable measurements dummy -heads are often used to model the average human head and body. They are suited for standardized measurements and for investigating the human spatial hearing and localization performance. The monaural Head-Related Transfer Functions (HRTFs) of the dummy-head can be used for various investigations. This paper uses the HRTF-set of a Brüel & Kjaer head and torso simulator focusing on the so called monaural head-shadow area, where one of the ears is shadowed by the head itself. Based on long-term measurements using the bare torso as well as other accessories (glasses, clothing etc.) on it, the extent of the head-shadow area will be presented in frequency and space. The head-shadow area is investigated in connection with the overall SNR of the measurement and sensitivity domains of the ears. Conclusions are drawn for binaural recognition in human spatial hearing using low-frequency 'bright spots' and high-frequency information during lateral-contralateral evaluation.