TPO 56

Both the passage and the lecture discuss the possible sources for sounds that Russian submarine sailors heard in North Atlantic and the Arctic Ocean, from the 1960s to the 1980s. The article proposes several explanations for these sounds. On the other hand, the professor argues that each of those theories has problems and opposes each one.

First, the passage claims that those noises were from orca whales trying to attract a mate during the courtship ritual. Nevertheless, the professor denies this idea and states that orca whales usually live near the surface of the water, whereas the submarines were in deep parts of the ocean. Moreover, if the orcas were the source of those sounds, submarines could detect them by their sonar systems. As a result, those sounds could not be the orcas' sounds.

Second, the reading indicates that those sounds come from massive invertebrates, called squids, that live deep in the ocean and have a soft body, so they cannot be detected by sonar systems. Nonetheless, the lecturer rejects this idea and illustrates that squids have been living in the deep sea all the time, but these sounds were first heard in the 1960s, and in the 1980s, they were disappeared. Therefore, it is unlikely that squids be the source of those sounds.

Finally, the author suggests that another country's submarines that were secretly patrolling the area were responsible for those sounds. However, the speaker refutes it, saying that the sources of those sounds were moving really fast in different directions, and Russian submarines did not detect any engine voice. She explains that no country has the technology to make such fast submarines with this amount of silence.