This paper takes note of the major influences of room acoustic effects on the fundamental frequency F0 of speech and its determination. A detailed description of room acoustic measures and effects is given. As a conclusion of those the dependency of the speaker to microphone distance (SMD) is to be studied combined with the reverberation time T60. Evaluation experiments aiming to find dependencies of the room acoustic effects are accomplished. In contrast to most of the studies which deal with reverberation, this paper proves that T60 cannot be the only measure to describe the behavior of systems in reverberant environments. Experiments studying the dependency on the SMD are new contributions within this paper. The experiments are an extension of the previous studies on the dependency on artificial reverberation, where twelve F0 estimation methods are compared. Here, two further methods are added and the systematic use of real measured room impulse responses (RIR) is applied. Apart from the SMD dependency other main contributions are the experiments of different disturbing effects on high and low F0. The results show male F0 estimation is significantly more sensitive to reverberation than female.