Answer:
Ultrasound.
Step-by-step explanation:
Hello,
In this case, it is necessary to remember that ultrasound is a high-wave frequency sound that is higher to that the human ear can notice. It covers wave frequencies higher than 20,000 waves per second, or 20,000 hertz (Hz). Furthermore, we are not able to hear ultrasound, even do, it is helpful to humans and some other animals in the detection of non-visible surroundings.
Best regards.