A Directional Audible Sound System using Ultrasonic Transducers

Abstract

Abstract-In general the audible sound has the characteristics of spreading, however the ultrasound is directional. This study used amplitude-modulating technique for an array of 8 ultrasonic transducers to produce directional audible sound beam. In this study sound field distribution for the directional audible sound beam has been investigated. The effect of different weightings varied with different frequency for the transducers on the directivity of the sound beam has also been evaluated. An optimization method was used to calculate the optimal weightings of the transducers for better directivity of the sound beam. Different optimal weightings also added to the carrier and sideband frequencies to control the difference frequency's beam width and side lobe amplitude. The results showed that the beam width can be controlled and good directivity of the sound beam can be obtained by using the optimization method.

Glasses for the blind using ping ultrasonic, ATMEGA8535 and ISD25120

“…The ultrasonic sensor block provides the input for the microcontroller. Ultrasonic is sound with a frequency greater than the upper limit of human hearing (greater than 20 kHz) [12,13]. The speed of sound depends on the medium the waves pass through, and is a fundamental property of the material.…”

A game-theoretic analysis of DoS attacks on driverless vehicles

“…Previous work has shown that host-level attacks can be mounted via sensor saturation [21], [18], [16] or by exploiting the impact of adversarial inputs on machine-learning techniques [9], [17], [10], [19], [4]. Up until now, no techniques have been proposed as to how attacks on individual hosts can be scaled.…”

“…Directional ultrasound acoustic jammers consist of an array of powered ultrasound transducers whose output is focused into a narrow beam with a distance range of a few tens of meters [21]. These were developed with (a short range) for medical imaging and (medium range) for sound entertainment systems [18]. Such precision engineering tools can be repurposed as attack tools to shine an acoustic spotlight to stealthily saturate vehicles deploying sonars.…”