What is the primary function of a hydrophone?

ہائیڈرو فون کا بنیادی کام کیا ہے؟

To measure air pressure in the atmosphere

To detect and record sound under water

To track the movement of satellites in space

To measure temperature changes in the ocean

A hydrophone is an instrument designed to detect and record sound underwater.

It's essentially the underwater equivalent of a microphone and is commonly used in:

Marine biology (e.g., studying whale calls or dolphin clicks)
Submarine and naval operations (e.g., detecting other submarines or ships)
Environmental monitoring (e.g., measuring underwater noise pollution)
Underwater research (e.g., studying seismic activity or underwater volcanic eruptions)