First there were soft underwater sounds; then very slowly one became aware of a figure at the back of the stage.

Acoustic survey - a systematic gathering of information on fish availability and abundance using underwater sound.

The tape begins with darkness and a roaring, bubbling underwater sound.

A new deckhouse was constructed aft to house underwater sound and electronic equipment.

Type 123A could detect the distance to underwater sounds but could not determine the depth.

Galaxy was acquired for the express purpose of research in underwater sound.

But it was also a device which picked up any underwater sounds.

The downed fighter plane was still making strange little underwater sounds as it settled into its new environment.

People who spend way too much time looking at spectrograms of underwater sound.

A dolphin's hearing is so good that it can detect underwater sounds from 25 kilometres away.