What is a hydrophone?

What is a Hydrophone ?

A Piezo hydrophone is a kind of underwater microphone designed to monitor underwater noise .  A typical piezo hydrophone works by detecting pressure changes in the surrounding environment and converting sound waves into voltage. The speed and distance of the sound wave propagating in the water is proportional to the pressure change , which will determine the nature of the electrical output transmitted.

Piezo sensor is the key element that is embedded in the hydrophone for underwater listening applications , a Piezo hydrophone utilize piezo sensor to detect sound presser waves produced by underwater vessels , animals and environment , A piezo hydrophone must hav a flat frequency response that is proportional to the magnitude of the sound pressure wave.

What is the working principle of a piezo hydrophone ?

Like a microphone are used to listen to the sound in the air , the Piezo hydrophone are used to listen the sound of underwater , Microphone convert sound in the air into electrical signals. The electrical signals can be amplified , recorded , played back through loudspeakers , and transmitted to telephone lines.  The electrical signals can be used to measure the characteristics of the sound, such as amplitude and frequency. Similarly, piezo hydrophones convert sound in water into electrical signals that can be amplified , recorded , played back over loudspeakers , and used to measure the characteristics of the sound. Hydrophones listen to the sound but do not transmit any sound .

How does a hydrophone work ?

By amplifying and recording electrical signals , a piezo hydrophone measures ocean sounds with great precision. While a single piezo hydrophone can record sounds in vertical direction, several hydrophone simultaneously positioned in an array , often several meters apart and result in signals that can be manipulated to listen with greater sensitivity than a single device. Omni-directional and hemi-directional hydrophone picks up sound from any direction and can used to track fish movements.