On the combined effects of early- and late-arriving sound on spatial impression in concert halls

This paper describes six new experiments involving subjective ratings of the listener envelopment, LEV, and the apparent source width, ASW, of simulated sound fields. Previous work has identified LEV and ASW as the principal components of spatial impression in concert halls and has shown that ASW is primarily influenced by the level of early lateral reflections and LEV by late-arriving lateral reflections. The new results in this paper show that LEV can result from nonlateral late-arriving sounds and demonstrate the conflicting effects of early- and late-arriving lateral sound on ASW and LEV when both are present, as would occur in real halls. While it is possible to create simulated sound fields with only either LEV or ASW, in typical concert halls, the balance between early- and late-arriving lateral sound will determine the relative importance of LEV and ASW. LEV and ASW are shown to be perceived when the critical components of the sound field are salient relative to other components. The results of the new subjective studies were used to estimate expected ASW and LEV in 16 halls. In these halls LEV is predicted to be the stronger component of spatial impression.