Is that a dolphin whistle I hear? No, it’s either a submarine or Harland Williams.

by • April 15, 2013 • Dolphin News, Dolphin ScienceComments Off8572


As we all know from watching The Hunt for Red October, submarine sonar operators have an almost super-human ability to identify underwater sounds. They can tell the difference between different types of military ships based solely on the sound produced by the engine, and it would be almost impossible to transmit man-made communication signals that a sonar operator couldn’t identify. But Chinese scientists have found a way to deceive even the best sonar operators, and they seem to have taken their lead from this scene from Down Periscope where Kelsey Grammer’s crew fools an enemy submarine into thinking they are a whale by having ‘Sonar’ Lovacelli (played by Harland Williams) imitate whale sounds. In this scene (in the above video), the enemy sonar operators dismissed the sounds they heard as a “biologic,” and the crew of the USS Stingray was saved (whale sounds start at 1:04):

It seems Mr. Williams was onto something. In a recently published scientific article, Chinese scientists described how they were able to hide information in artificial dolphin vocalizations with the goal to have sonar operators dismiss these covert communication signals as being natural dolphin sounds. The system works by first transmitting a series of dolphin whistles that synch up both the sending and receiving systems. This is followed by a series of dolphin click sounds – the same kinds of clicks used in dolphin echolocation. By varying the time delay between the clicks, the scientists were able to include up to 6 bits of binary data, allowing for a rate of 37 bits per second of digital information to be transmitted. The scientists field tested the system on Lianhua Lake in Heilongjiang, where two ships spaced 2 kilometers apart were able to reliably transmit information via these fake dolphin vocalizations. Hypothetically, even the most experienced sonar operator would, upon hearing these artificial dolphin sounds, dismiss them as naturally occurring animal noises, allowing for secret messages to be conveyed. So the next time you hear dolphin click sounds when swimming under water, this is what might be happening:

1) Dolphins echolocating

2) Navy submarines transmitting a secret coded message

3) Harland Williams filming Down Periscope 2

Here’s the article in question, which was recently published in the The Journal of the Acoustical Society of America:

ResearchBlogging.orgLiu S, Qiao G, & Ismail A (2013). Covert underwater acoustic communication using dolphin sounds. The Journal of the Acoustical Society of America, 133 (4) PMID: 23556695

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