Hydrophone (noun)

A device used to detect and record underwater sounds, often used in oceanographic research and military applications.

Origin:

Derived from the greek words 'hydro' meaning water and 'phone' meaning sound.

Examples:

1. The hydrophone was used to listen to the songs of whales in the ocean.
2. The hydrophone was an important tool in studying the impact of human activity on the underwater environment.
3. The hydrophone was sensitive enough to detect even the faintest underwater sounds.
4. The hydrophone was part of a larger underwater monitoring system used by scientists.
5. The hydrophone was used to track the movement of submarines during military exercises.