Statistical Measures of Early Reflections of Room Impulse Responses

Rebecca Stewart; Mark Sandler
DAFx-2007 - Bordeaux
An impulse response of an enclosed reverberant space is composed of three basic components: the direct sound, early reflections and late reverberation. While the direct sound is a single event that can be easily identified, the division between the early reflections and late reverberation is less obvious as there is a gradual transition between the two. This paper explores two statistical measures that can aid in determining a point in time where the early reflections have transitioned into late reverberation. These metrics exploit the similarities between late reverberation and Gaussian noise that are not commonly found in early reflections. Unlike other measures, these need no prior knowledge about the rooms such as geometry or volume.