Acoustic signature

Few days ago, I read news that several Russian navy ships are anchoring in Cuba, and the American government is on alert and has sent a fleet of navy ships to march close to Cuba. 

Russia and Cuba have a socialist regime, and Russia always supports Cuba in every respect.

Then I read somewhere that a big Russian navy ship is anchoring close to the UK and Europe. 

Europe is worried about the presence of this big Russian navy ship in such a close proximity in sea area.

Because this Russian navy ship is one of the top spy navy ships of Russia and has very sophisticated complex instruments needed for exploring from the surface to deep underwater as well as territorial activities. 

One of them is preparing acoustic signatures of underwater arms, from old to new modern submarines or any activities emitting acoustic waves. 

Russian navy technicians can record those sounds, whether fine or noisy, using recording instruments and then use them to identify particular arms, navy ships, submarines, or any activity. 

These acoustic signatures can be used during wartime to protect Russia from any destructive actions by the enemy.

Moreover, such acoustic signatures can also be used to improve and modernize present instruments needed to protect humanity from natural, unpredictable calamities.

Global players take the world as a football playground, and they are always worried that an enemy's action might chancely score a goal.