2020/09/11 by Eichenauer, Anja, Baumann, Uwe, Weißgerber, Tobias
Medicine · #610 Medical sciences #ILD #Medicine #Nachhall #Raumsimulation #SRM #Sprachverstehen #interaural level difference #reverberation #room simulation #räumliche Entmaskierung #spatial release from masking #speech perception
paper · doi:10.3205/zaud00010
In everyday life listening situations, communication is characterized by a variety of challenging acoustic scenes. Usually, background noise sources are present and, additionally, direct sound in rooms is reflected from walls and surfaces. These reflections affect speech perception. However, audiological assessments are usually performed in rooms with low reverberation time. This work aims at implementing and evaluating a room simulation system to examine hearing ability in everyday life listening situations with different acoustic properties and reverberation. With a room simulation software sound propagation was calculated in relation to the room geometry and acoustic room parameters. The direct sound and its reflections are presented according to their direction by using a multichannel playback system with 128 loudspeakers. Any desired room can be reconstructed in the laboratory under realistic and controllable acoustic conditions. The room simulation procedure was evaluated using an empty auditorium with different degrees of absorption properties. Technical measurements of reverberation time (RT) and distinctness (D50) showed good agreement with the model data. Additionally, interaural level differences (ILDs) were recorded and correlated with speech reception thresholds. ILDs are reduced up to 10 dB with increasing reverberation. At the same time, spatial release from masking (SRM) compared to free field conditions decreased up to 5.5 dB SNR. The determination of speech discrimination using the introduced room simulation system is a useful complement to established audiological measurements. The hearing performance under defined acoustic properties can be determined reproducibly and reliably.