1. An underwater microphone used to detect and record sound waves in water.
Usage: technical; commonly used in marine science, oceanography, and underwater research

Examples

• Marine biologists deployed hydrophones to monitor whale songs in the ocean.
• The research team used hydrophones to detect seismic activity on the ocean floor.
• Hydrophones are essential instruments for studying underwater ecosystems and animal communication.
• The submarine was equipped with sensitive hydrophones to listen for other vessels.
• Scientists placed hydrophones around the coral reef to record the sounds of fish and crustaceans.