A optimization method for a sound playback performed by a set-top box including at least one speaker, and to which at least one camera is secured. The method include the steps of: acquiring an initial image produced by the camera while the set-top box is in an initial position and in an initial orientation, the set-top box thus using initial audio parameters to optimize the sound playback; then, acquiring at least one current image; analyzing the current image and the initial image to detect a change of position and/or orientation of the set-top box; performing at least one corrective action to optimize the sound playback.