The suppression device for outdoor noises in indoor space solves the technical problems on realizing better sound insulation effect within the room space and creating a quiet atmosphere for people's living environment. The structure includes an anti-noise sound source synchronized to and invert with outdoor noises. The circuit structure of suppression device includes a directional reception and processing circuit for outdoor noises, a attenuation control circuit, a multi-channel digital amplifier circuit, and loudspeaker being installed at the inlet of indoor noises. The directional reception and processing circuit for outdoor noises processes the noise signals collected from the outdoor environment and generates the inverted-phase signals, and then transmits them to the input terminal of attenuation control circuit. After being processed with attenuation by attenuation control circuit, the reverse-phase signals are sent out to input terminal of multi-channel digital amplifier circuit, which then enables the loudspeaker to generate noise compensation signals inverted to outdoor noises. This invention can provide the whole system with noise suppression capability over 28 dB.
