What happened to hamming?

The mysterious sea often makes various sounds, collectively known as "Haiming". The sound sources of some ocean sounds are well known, such as billowing waves and their ringing, ringing caused by atmospheric precipitation, earthquakes and volcanic activities, and sounds made by fish and other marine life. But the sound source of some sea sounds is still a mystery. In the southeast sea area of Naozhou Island in Zhanjiang, Guangdong, China, when the wind and cloud suddenly change, the weather is abnormal, and the storm is coming, there will be waves of rhythmic "meowing" sounds on the sea. This sound is like a muffled thunder rolling, one high and one low, strewn at random. According to the local old man, the French put a water drum in the water when they built the international lighthouse on Naozhou Island a long time ago. The water drum is equivalent to a sea state detection alarm, which is specially used to forecast the sea weather. It can send people information about the changes of wind and waves at any time, and this "meow" sound is made by it. However, no one has seen the stone drum immersed in water, and I don't know where to put it. The relevant departments have specially sent boats to patrol the southeast waters of Naozhou Island, and found nothing.

1969, a group of sea pigs were found swimming in this sea area, so the locals thought that the sea song might be the howl of sea pigs, but it was also produced in places where there were no sea pigs. Obviously, this statement is wrong.

During the period of 1976, the sound of sea singing in the southeast waters of Naozhou Island was weaker than before, so people who hold the "water drum theory" think that this is because the water drum is too old, which leads to its function declining day by day. Those who hold the "theory of sea pigs" believe that this is the result of the obvious increase of people's activities in this area in recent years, which has affected the normal activities and life of sea pigs and made them migrate.

These two statements seem to have some truth. It is still a mystery where the sound source of Shanghai Ming is located in the southeast waters of Naozhou Island.