On existence of optimal boundary value between early reflections and late reverberation

Enhancement of speech distorted by reverberation is issue of the day. The problem has been actively studied in the last decade. However, it is still extremely difficult to find clear recommendations on choice of boundary value between early reflections and late reverberation, optimal in sense of such criteria as speech recognition accuracy and speech quality. Another problem is getting of simple pre-processor of speech dereverberation. The problems are investigated in the paper.