Communication device comprising a mouthpiece

A communication device comprising a mouthpiece intended to be worn in the mouth of a subject comprising:

• an acoustic conduction plate intended to be bitten by the user;
• a vibrating element configured to convert an audio input into an acoustic output, the vibrating element being coupled to the acoustic conduction plate so as to transmit said acoustic output to said plate;
• a labial portion to accommodate the user's lips, and
• a lumen for passing air through the labial portion and formed at least in part by walls of the labial portion, wherein the labial portion is configured so that said walls of the labial portion are deformable between a first configuration in which opposite walls of the labial portion are not in contact, so as to allow air to pass by the lumen and a second configuration in which the opposite walls of the labial portion are in contact, and wherein exterior surfaces of the labial walls have a concave shape at rest.