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When some plants are dehydrated or under some other form of stress, they cry a mournful melody made of ultrasonic clicks.

The team was able to remove the expensive metals and circuit components by placing leaftronics in an ultrasonic acid bath.

Many pedagogical and scientific sources suggest that the highest pitches reached in classical singing can only be produced with a so-called "whistle" voice register, in analogy to ultrasonic vocalizations of mice and rats.

Lighting a gas grill, getting an ultrasound, using an ultrasonic toothbrush -- these actions involve the use of materials that can translate an electric voltage into a change in shape and vice versa.

When they hear a bat nearby, they respond with their own ultrasonic signal, and for the past 30 years, no one has known why.