Google's Home, Amazon's Echo and Apple's Siri all responded to ultrasonic commands Voice-controlled ... at high frequencies that can be heard by dolphins but are inaudible to humans.

But a hackier way would be to build a parametric speaker that focuses soundwaves into a narrow beam like [Shane] did with this ultrasonic sound gun. As the directivity of a soundwave depends on ...

Local officials put up warning signs and set up buoys that emit ultrasonic sound waves to ward off dolphins, as they rely on echolocation. The Coast Guard warns against approaching dolphins and to ...

Dolphins have an inbuilt echolocation system that generates ultrasonic waves and determines characteristics of objects using reflected sound. They also use it to communicate with each other.