Air intake silencing device especially for turbocharged engines or air conditioner and intake circuit with such a device

The device has a pipe section (1) formed by two semi-shells (3, 4) partitioned with longitudinal partition walls extending from a bottom wall to a sealing surface of the respective semi-shells. The partition walls contact at their free edges (12). Each edge has notches (14) constituting, in the assembled state of the semi-shells, an opening for communication between a resonance chamber and a main pipe section (5). An independent claim is also included for an air inlet circuit of an internal combustion engine or an air conditioning device equipped with a noise reduction device.