Air intake silencing device

The noise attenuation device comprises a pipe section (1) forming a section of the air inlet circuit of the turbocharger. It is fitted with a first group of external circumferential chambers (5) located in parallel about the pipe and communicating with it through parallel openings (2) around the pipe section. An additional chamber (6) located in series with the first group of chambers communicates through an opening (3) with the pipe section. An Independent claim is included for an engine air inlet circuit fitted with the noise attenuation device.