In the exclusive economic zone, the coastal State shall have the exclusive right to construct and to authorize and regulate the construction, operation and use of: (a) artificial islands; (b) installations and structures for the purposes provided for in article 56 and other economic purposes;
Infrasound may also be used for long-distance communication in African elephants. These calls range from 15â35 Hz and can be as loud as 117 dB, allowing communication for many kilometres, with a possible maximum range of around 10 km (6 mi).
(Sound at frequencies too low to be audibleâabout 20 hertz or lowerâis called infrasound.) The familiar medical ultrasound images (of a fetus in the womb, for example) are made by directing ultrasonic waves into the body, where they bounce off internal organs and other objects and are reflected back to a detector.