A noise suppression device and method

The present invention provides a noise suppressing device and a method thereof. The device is mainly composed of a cavity, a plurality of ducts, an electroacoustic sensor, a loudspeaker and a noise suppressing circuit; wherein, the sectional area of the cavity is greater than the sectional area of the ducts; one duct is connected with the cavity so as to provide an external acoustic signal to enter the cavity; another duct is connected with the cavity so as to send the processed acoustic signal an ear canal; the electroacoustic sensor is used for receiving the acoustic wave signal which enters the cavity and converting thereof into an electronic signal and then sending thereof the noise suppressing circuit; the loudspeaker is used for receiving the electronic signal which is generated by the noise suppressing circuit and generating an opposite phase acoustic signal; the noise signal with high frequency can be suppressed by a low pass acoustic wave filter which is formed by the ducts and the cavity; the opposi