The invention relates to a device for detecting physiological sounds, the device comprising a thin film, and a first conductive element for conducting sounds, the conductive element being located on the thin film. In some embodiments, the detection device comprises a cavity; the thin film is a part of the cavity. The volume of the cavity is variable; the volume of the cavity is reduced, either when the conductive element contacts the skin of a human or a mammal, or before the conductive element contacts the skin of a human or a mammal, or after the conductive element contacts the skin of a human or a mammal. The device of the inventions can significantly improve the detection sensitivity and resolution of physiological sounds, and can give early diagnosis pathological sounds, for example, heart failure can be detected by heart sound diagnosis.