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.