At the contact with the ground, the tyre we schematize as a torus  is deformed. This deformation which is assimilated to an ellipse engenders in the torus  an acoustic wave, when the tyre is in rotation with a constant angular velocity W. R and  denote, respectively, the generating circle radius and the sound speed. A previous work [1], at the time scale  set into evidence the acoustic wave problem. An other study [2], by scrutinizing the acoustic wave problem, showed that  is associated to a resonant mode. This last study also modeled numerically the resonance phenomenon in  In this work, we proved that beside there exist nonzero resonant modes which derive from the road profile. We then determine explicitly these modes and by examining one of them, we show that,  at the resonance, the acoustic wave moves in sinusoidal way, by increasing in amplitude.

acoustic wave, resonance, air, torus, pneumatic.