The ocean is alive with sound. While light fades quickly in water, sound travels farther and faster, becoming the primary way to explore, communicate, and detect in the deep. Underwater acoustics, or hydroacoustics, is the science of sound in water—essential for marine operations, wildlife studies, and submarine navigation.
How Sound Travels in Water
What Influences Underwater Sound Propagation?
Temperature
Warmer water speeds up sound.
Pressure
Increased depth compresses water molecules, also increasing sound speed.
Salinity
Saltier water = denser water = faster sound travel.
Sound in Water vs. Air
Because of this difference, radar is used in air, but sonar is used underwater.
Characteristic
Air
Water
Speed
~343 m/s
~1,493 m/s
Medium Density
Low
High
Sound Transmission
Short-range
Long-range
Application Focus
Speech, music
Sonar, marine communication
Marine Mammals and Acoustic Communication
Marine mammals like whales, dolphins, and seals rely on acoustic signals to:
Navigate
Locate food
Communicate socially
Find mates
Types of Sounds Used:
Sound serves as the primary medium of communication for mammals, allowing them to navigate, locate prey, and communicate with conspecifics over great distances. These animals produce a wide range of sounds, including clicks, whistles, moans, and songs, each carrying distinct meanings and functions within their social and ecological contexts. Researchers use a range of methods to study mammal communication including passive acoustic monitoring and controlled experiments.
Hydrophones (fixed or towed)
Passive Acoustic Monitoring (PAM) systems
Controlled experiments for behavior studies
Key Concepts in Underwater Acoustics
Frequency
Measured in Hertz (Hz) Low = deep rumble, High = sharp click
Decibels (dB)
Measures intensity +10 dB = ~10x increase in sound energy
Noise Pollution
Caused by shipping, construction, sonar Affects communication, feeding, migration of marine animals
Real-World Challenges and Solutions
The Problem
Underwater noise from ships and industry can:
Mask whale calls
Disorient dolphins
Interfere with fish behavior
Impact ecosystem balance
The Solution
Monitoring + Mitigation = Marine Protection
Quieter vessel design
Alternative shipping routes
Continuous noise assessment
Public awareness campaigns
Sinay's Acoustic Technology in Action
Sinay leads the charge in revolutionizing maritime operations with cutting-edge digital technologies tailored for environmental sustainability and operational excellence. Among Sinay’s innovations are advanced sonar systems, boasting unparalleled precision in underwater monitoring and hazard detection.
Smart Sonar Systems
High-precision acoustic sensing Detects hazards and marine life Reduces collision risks
Underwater Communication Networks
Powered by PAM buoys Real-time data transmission Secured via encrypted protocols
