What is a hydrophone?

A hydrophone is specifically designed as an underwater microphone that captures and records sound waves in the ocean. This application is vital in various fields, including marine biology, oceanography, and naval operations, as it allows researchers and professionals to monitor and analyze underwater sound environments. Hydrophones can pick up a wide range of sounds, from marine animal vocalizations to human-made noises, contributing significantly to our understanding of underwater acoustics and the health of marine ecosystems.

The other choices, while related to oceanographic studies, serve different purposes. Measuring water pressure pertains to tools like pressure sensors or deep-sea pressure gauges, mapping the ocean floor involves sonar systems (not typically classified as hydrophones), and analyzing chemical properties of seawater refers to chemical analysis equipment. Each of these has distinct functions that do not align with the defining characteristics of a hydrophone.