FRONTIERS IN OCEANIC RESEARCH 47 



The Chairman. Do you mean by that, the disturbances distract 

 from the detection of submarines ? 



Dr. Wakelin. They do, indeed, and they form a large part of the 

 whole ambient noise background which must be separated from what 

 you are looking for. 



In a great many cases the sounds that are produced here are in the 

 same frequency range in the sound spectrum with that which is 

 produced by submarines and ships. So it is a delicate matter to be 

 able to take the background noise away and improve our signal-to- 

 noise ratio in looking for and locating submarines. 



Mr. Miller. Those are only a few of the noises you get too. 



Dr. Wakelin. Yes. 



Mr. Miller. There are dozens of them. 



Dr. Wakelin. Yes, there are, sir. There are additional noises also 

 from the whole dynamics of the wave motion. 



Mr. Bass. How are these noises recorded, Mr. Secretary ? 



Dr. Wakelin. These are recorded, part of them on a sonar device, 

 and part of them just using a straight transducer, with a normal audio 

 frequency amplifier. 



Mr. Bass. If you were a skindiver, would you hear the same thing ? 



Dr. Wakelin. Yes, if you had earphones with an audio amplifying 

 device, you could pick up these same sounds. It would be an in- 

 teresting experiment to do. 



The Chairman. A fresh water fish would produce different noises 

 from that? 



Dr. Wakelin. They probably would produce noises characteristic 

 of the fish themselves, yes. 



The Chairman. I had heard some of fresh water fish. 



Dr. Wakelin. Yes. 



Mr. Fulton. You never had a characteristic pattern picked up 

 of Soviet submarines, have you ? 



Dr. Wakelin. I am afraid I can't answer that, sir. 



The Chairman. Can you pick up the noise of Polaris submarine? 



Dr. Wakelin. Oh, yes. 



The Chairman. You could distinguish that from non-Polaris sub- 

 marine ? 



Dr. Wakelin. I am afraid I can't answer that, sir. 



The Chairman. Just proceed with your statement. We don't want 

 to go too far afield. 



Dr. Wakelin. It is simple enough to define research in underwater 

 acoustics as the study of the generation, propagation, and reception 

 of somid in the ocean. And yet we have just heard that the prob- 

 lems involved are as complicated as the ocean itself. To exploit fully 

 this complex environment for offensive and defensive purposes, we 

 must know and understand the characteristics of the oceans, and we 

 must know why and when these characteristics change. 



Other activities using knowledge of the oceans include the fore- 

 casting services performed by the Hydrographic Office. On the 

 basis of sea and wave forecasts of the North Atlantic and Pacific 

 Oceans, ships can be routed in such a manner as to arrive at their 

 destinations more quickly and with less chance of damage from heavy 

 sea conditions than might otherwise be the case. 



