TOEFL Integrated writing TPO32

The reading and the speaking are discussing some strange sounds that Russian submarines sailors were hearing in the North Atlantic and Arctic Oceans and they call them quackers. However, they do not really know about the source of those sounds and there are some arguments about them. While reading provides some reasons, the lecturer casts doubts about the mentioned reasons in the reading.
To begin with, the reading states the first theory that those strange noises were related to the whales while whose male and female were calling each other for courtship ritual. In contrast, the lecturer rejects this notion by this idea that Ocra whale sweam near the surface of the ocean and it is unlikely that the submarine which is under the water most of the time could hear those sounds, besides this can not be plausible that Russian submarine could detect the Ocra whales sounds via their constraint facilities.
Secondly, the reading mentions that those strange sounds caused by huge squids which live in deep parts of the ocean and emit sounds when they approach the submarine. Nonetheless, the speaker refutes this idea by this theory that the sounds were being heard in 1960s but abruptly they were disappeared till 1980s. So these uncontinous sounds can not be regarded the squids which were living and hanging in the ocean all that period and they were nat absent for one decade.
Finally, the last reason that is mentioned by reading which states that the noises were due to the presence of other submarines in the ocean, was rejected by the lecturer because of this notion that the source of sounds was changing its direction quickly. And there were not designed any submarine that would have such novel technology could be fast and silent to change the direction instantly in that time.