Omni-directional sound source using facing ultrasonic transducer arrays
We present a new omni-directional sound source using facing ultrasonic transducer arrays. Ultrasonic transducers have been studied for sensors in acoustic sensing, arrayed parametric loudspeakers, or non-contact manipulation. In this research, ultrasonic transducer arrays are placed face-to-face on a straight line, and the arrays radiate sound with different ultrasonic frequency each other from both sides. Then the audible sound with differential frequency of the ultrasound signals is omni-directionally emitted. In this report, we fabricated sound source employing a facing ultrasonic transducer array, and evaluated the frequency characteristics and directivity of the sound source experimentally. This result suggests that it is possible to produce simpler, smaller, and light-weighted omni-directional loudspeakers with higher design like a ring and polyhedron.
Authors: Kyoka Okamoto (Tokyo Metropolitan University) and Kan Okubo (Tokyo Metropolitan University)