WW2 Allied Ship Siren Noise (what is it? Help!)

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I am trying to identify a noise made by allied shipping (warships?) during WW2. I've heard it in films and games but I can't find any information on it. I can only ever remember hearing it in the aftermath of a German Torpedo attacks. The noise itself is similar to the high pitched sound sound sometimes made by Killer Whales. Any info is appreciated! The sound sample is from "The Imitation Games" the short scene where a convoy is hit by a wolfpack of German U boats.
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