Système Acoustique

L'invention concerne un système acoustique (1) comprenant : - une enceinte ultrasonore (10) qui comprend au moins deux sources et qui est conçue pour produire un faisceau ultrasonore focalisé ; - un système de captation (20) qui comprend au moins un microphone (21) et qui est adapté à enregistrer une onde sonore ; - une unité électronique de commande et de traitement du signal adaptée à piloter l'enceinte de manière à produire un premier son audible dans une zone d'écoute et à extraire de l'onde sonore un second son audible provenant d'une zone de captation superposée au moins en partie à la zone d'écoute. Figure pour l'abrégé : figure 1. The invention relates to an ultrasonic attenuator (100) for a microphone (21) comprising at least one input channel (120, 140) and at least one expansion chamber (110, 130) arranged in series to communicate with one another, the expansion chamber (110,130) being located between the input channel and the microphone (21), the channel and the expansion chamber each having a maximum flow-through cross section, the maximum flow-through cross section of the expansion chamber being strictly greater than the maximum flow-through cross section of the input channel. The invention also relates to an acoustic system (1) comprising: - an ultrasonic chamber (10) which comprises at least two sources and which is designed to produce a focused ultrasonic beam; - a capture system (20) which comprises at least one microphone (21) and which is designed for recording a sound wave; - an electronic control and signal processing unit designed for controlling the chamber so as to produce a first audible sound in a listening area and to extract from the sound wave a second audible sound coming from a capture area superimposed, at least partially, on the listening area.