1. A device for determining room-optimized transfer functions for a listening room derived for the listening room and serving for room-optimized post-processing of audio signals in spatial reproduction, wherein the spatial reproduction of the audio signals is emulated by means of a binaural close-range sound transducer using known head-related transfer functions and using the room-optimized transfer functions, wherein a room to be synthesized may be emulated based on the head-related transfer functions, and wherein the listening room may be emulated based on the room-optimized transfer functions, wherein the device is configured to analyze room acoustics of the listening room and to determine, starting from analyzing the room acoustics, the room-optimized transfer functions for the listening room where the spatial reproduction by means of the binaural close-range sound transducer is to take place, wherein the device comprises a storage in which may be deposited a plurality of room-optimized transfer function families for a plurality of listening rooms, wherein emulating the spatial reproduction is based on interaural features, balance features and distance features, wherein the interaural features comprise a connection between a direction of incidence in the medial planes and an individual or non-individual head-related filtering, wherein the balance features comprise a connection between a lateral direction of incidence and a difference in volume and/or a connection between the lateral direction of incidence and a run-time difference, wherein the distance features comprise a connection between a virtual distance and frequency-dependent filtering and/or a connection between the virtual distance and an initial time gap and/or a connection between the virtual distance and a reflection behavior.