Underwater acoustics is the scientific study of natural and man-made sounds underwater.
Behind them, the fires of the Second Legion faded into nothingness and before long theirs were the only man-made sounds to break the night.
The only man-made sound around here was the water dripping from my clothes and chest harnesses on to the leaf litter.
No streetlights or man-made sounds puncture the setting.
The sound pressure level of large rocket engines has been measured at greater than 200 decibels - one of the loudest man-made sounds on earth.
A sense of peace pervades this moorland, unbroken by man-made sound or any visual disruption.
These devices were meant to simulate natural and man-made sounds, such as trains and bombs.
The slap of their feet on the deck was about the loudest man-made sound.
He opened his eyes, glanced at the sonar indicator, which was pointing in the direction of the largest regular, man-made sound.
Vocal mimicry can include conspecifics, other species or even man-made sounds.