Abstract: Disclosed is an acoustic transducer for converting a sound signal into an electric signal, including a mobile element movable under the effect of the sound signal, a fixed element opposite the mobile element, a recess, and a dissipative element between the mobile and fixed elements. The coupled system has a natural frequency corresponding to a resonance frequency of the transducer set at maximum sensitivity. The mobile element, the fixed element, the dissipative element and the recess are configured so the quality factor of the acoustic transducer>2. The recess has a straight prismatic, cylindrical, or frustoconical shape, the mobile element forming a first base of the prism, cylinder, or frustum, the fixed element being inside the prism, cylinder or frustum, over the second base of the prism, cylinder or frustum. Such a transducer also incorporates an analogue filtering function for filtering the signal around the natural frequency of same.

Abstract: Some embodiments are directed to a system for locating an object furnished with a tag in a predetermined space. The tag is interrogatable remotely by an RFID reader. According to the invention, a zone of sound is created with an ultrasound generator. A sound wave of frequency f1?f2 is present in this zone. The tag is equipped with an acoustic sensor able to sense the signals of frequency f1-f2 and this acoustic sensor is designed together with the tag to modify the content or the level of the RFID tag response signal when the acoustic sensor receives a signal of frequency f1-f2. The RFID reader is then able to locate the object in the zone of sound when it receives the modified response signal from the RFID tag or when it no longer receives any response signal from the RFID tag.

Abstract: Disclosed is an acoustic transducer for converting a sound signal into an electric signal, including a mobile element movable under the effect of the sound signal, a fixed element opposite the mobile element, a recess, and a dissipative element between the mobile and fixed elements. The coupled system has a natural frequency corresponding to a resonance frequency of the transducer set at maximum sensitivity. The mobile element, the fixed element, the dissipative element and the recess are configured so the quality factor of the acoustic transducer>2. The recess has a straight prismatic, cylindrical, or frustoconical shape, the mobile element forming a first base of the prism, cylinder, or frustum, the fixed element being inside the prism, cylinder or frustum, over the second base of the prism, cylinder or frustum. Such a transducer also incorporates an analogue filtering function for filtering the signal around the natural frequency of same.