During World War II underwater-sound men were puzzled to hear weird noises that were not made by ships. Now it is known that many marine species emit, among other sounds, chirps, whistles ...
making every human-made underwater noise particularly disruptive for ocean dwellers. For marine mammals like whales, dolphins, sea lions and seals, sound isn't just noise—it's their primary mode ...
However, according to both, the government memo does not say exactly when the sound was heard on Tuesday. Deep-sea experts told the BBC that it is hard to determine what these noises might be ...