Abstract: Whisper is a common mode of human communication in public.The earlier study about whispers is focused on the phonetics and medicine,and now,more attention has been paid to applied research with the development of technology.Firstly,the characteristics of whispers in physiology,acoustics and perception are introduced,and the main differences between normal and whispered speech in source and vocal tract transfer function are indicated.Then,the features extracted from whispered speech and corresponding methods are analyzed,based on these,the achievement of applied research during recent years has also been discussed.Finally,the future challenges and development trends of whispers are presented.