Time reversal of acoustic waves


For the International year of Physics, Nokinomo realised the first public demonstration of time-reversal of acoustic waves.

Time-reversal is a physical process that allows a sound wave to return to its source.

The glass plate is equipped with 8 piezoelectric sensors. These allow detecting vibrations on the plate. When you tap the glass, a wave is produced and travels on the whole surface of the plate.

This wave is numerically registered. Then the computer time-reverses the wave and re-emits it. The wave returns to the point where it was emitted.

This phenomenon is sensitive; you feel a constant pulsation at the impact point. The sound produced while you tap the glass has returned to its source.

This installation has been realized in partnership with the French Society of Physics (Société Française de Physique), the Acoustic Laboratory (le Laboratoire Onde et Acoustique), the French National Centre of Science (le CNRS), the Research Ministry (le Ministère délégué à l'Enseignement supérieur et à la Recherche),the ESPCI and Sensitive Object.


Société Française de Physique
Laboratoire Onde et Acoustique
Ministère délégué à l'Enseignement supérieur
et à la Recherche
Sensitive Object