Ultrasonic whistle
An ultrasonic whistle generated sounds with frequencies beyond what a typical Human could perceive.
History
Back in 27 ABY, Viqi Shesh employed an ultrasonic whistle as a means to trigger a Yuuzhan Vong device. Upon sensing the ultrasonic sound, the device would release a mist of spores designed to induce sleep within the residence of her intended victims, the Solo family.