前方空间环绕声的四扬声器虚拟重放
Virtual reproduction of surround sound in frontal space using four loudspeakers
-
摘要: 考虑头部转动带来的动态因素对听觉垂直定位的贡献,提出了前方空间环绕声的四扬声器虚拟重放方法。4个扬声器分别布置在水平面左前、右前以及高仰角的左前上、右前上方向,并采用听觉传输信号处理的方法将多通路空间环绕声信号转换为4个扬声器的重放信号。以9.1通路空间环绕声虚拟重放为例,采用头相关传输函数对双耳声压及其包含的定位因素进行分析表明,该方法可以产生正确的双耳时间差及其随头部转动的变化,从而产生合适的侧向定位双耳因素和垂直定位的动态因素。而心理声学实验结果表明,该方法可以重放稳定的前方空间的水平和垂直虚拟源。因此,四扬声器布置结合听觉传输处理足以重放前方空间环绕声的垂直定位信息,实现多通路空间环绕声的向下混合与简化。Abstract: By considering the contribution of dynamic cue to auditory vertical localization,a method for virtual reproduction of surround sound in frontal space using four actual loudspeakers is proposed.The four actual loudspeakers are arranged in the left-front and right-front directions in the horizontal plane,as well as left-front-up,right-front-up directions in a higher elevation plane,respectively.Transaural signal processing is used to convert the multichannel sound signals to the signals for the four actual loudspeakers.Virtual reproduction of 9.1 channel sound is taken as an example.The analysis of binaural pressures and corresponding localization cues using head-related transfer functions indicates that the current method is able to recreate correct interaural time difference and its dynamic variation with head turning,and thus able to create appropriate binaural cue for lateral localization and dynamic cue for vertical localization.Resultsof psychoacoustic experiment indicate that the current method is able to recreate stable horizontal and vertical virtual source within the frontal-hemispherical directions.Therefore,combined with transaural processing,the four loudspeakers arrangement is enough to reproduce the vertical localization information in frontal space and realize the down-mixing and simplification of multichannel spatial surround sound.