In concert hall acoustics, the perceived spatial impression and/or spaciousness are characterized by the two attributesapparent source width (ASW) and listener envelopment (LEV). For LEV there are no clear consensus across theresults of previous work. This paper aims to discuss the research performed on LEV and how these research resultsare confirming or contradicting each other. There is a consensus on the arrival angle of the later sound energy and itsinfluence on LEV, whereas there is no clear agreement on the delay time and frequency content of the latereflections.