关键词: 视听一体化, 声源干信号, 建筑声学仿真, VR技术, 混响感, 感知声源宽度, 声学主观评价

Abstract:

In the article, the multi-channel recording signal of Mozart's Symphony No. 40 was selected as the source dry signal, and the Tianjin Cultural Center concert hall was used as an example to simulate the sound field using the architectural acoustics simulation software ODEON. The symphony orchestra was divided into 49 point sound sources according to musical instrument, corresponding to the directivity of each musical instrument respectively. Five typical receiving point positions were set in the audience seat area, and the binaural impulse response from each sound source point to the receiving point was calculated respectively, then use binaural impulse response to convolve with the instrument signal corresponding to each sound source point, and finally the 49 resulting audio signals were synchronized and played together to synthesize the multi-source audible signal of the orchestra. At the same time, according to the traditional audibility method, set a point sound source in the center of the symphony orchestra, calculate the binaural impulse response from the point sound source to the receiving point, and then use binaural impulse response to convolve with the signal of the symphony composed of 49 dry signals and mix it into a single sound source audible signal. In terms of vision, firstly, the 3D model of the concert hall was established in sketch up and the real materials were given to each surface. The model of sketch up was output to the VR virtual reality simulation software SIMLAB composer, in which the parameters such as light, material and environment were adjusted. The virtual model was rendered and baked with adjusted information parameters to obtain a better sense of immersion. HTC VIVE Cosmos glasses were used to output VR virtual scenes and to simulate the three-dimensional vision of the hall. During the architectural acoustics audio-visual experiment, the subjective evaluation differences of Reverberance and ASW (Apparent Source Width) of audible signals convoluted by multiple sound sources and single sound source were compared under the condition of with or without VR visual signal. The experimental results show that the audible signal convoluted by multiple sound sources can significantly improve the Reverberance and ASW, and the improvement degree of different receiving points is different. Due to the significant difference in sound quality between the single-source and multi-source audible signals, the listening test participants in the architectural acoustics and audiovisual experiment focused more on the improvement of spatial sound quality. The addition of VR visual signals did not significantly improve the subjective evaluation results of the audible signals.

Key words: audio-visual integration, sound source dry signal, architectural acoustic simulation, VR technology, reverberation, perceived sound source width, acoustic subjective evaluation