Summer for many of us means the splash of waves, the rustle of sand under our feet and the cries of seagulls In order to hear these and other sounds, you don’t have to be on the coast at the water’s edge It is enough to put a large twisted shell to your ear and hear the sound of the surf Thanks to the spiral-shaped shells of mollusks, the melodies of the waves reach us across thousands of kilometers and warm us in the winter cold August 13th is Shell Noisy Day Since ancient times, the skeletons of sea mollusks have attracted people who treated them as precious objects Cowrie shells served as currency for the peoples of Asia, the Middle East and Africa who lived in these lands in the 13th century BC Among the ancient Egyptians, bags of shells were considered symbols of wealth; the Moi, Creole, Mali and Mande tribes used them as a dowry for brides Shells became decorations - beads, pendants and bracelets According to West African beliefs, wearing a cowrie necklace helped cure infertility The Hohokam tribes, who lived in southwestern North America, carved figures of birds, snakes, dogs and lizards from shellfish skeletons For religious purposes, shells were used as containers for blessed water and as trumpets, the sound of which eliminated negative energies during rituals A white shell with a spiral twisting to the right is a symbol of the superiority of the Buddha's teachings over other beliefs In Christianity, scallop shells are associated with Saint James, becoming a symbol of pilgrimage to the mountain where the tomb of the apostle is located A touch of mysticism and mystery gives twisted shells their ability to make the sound of waves There are several explanations for what a person hears when he puts the shell of mollusks of the family Strombidae and other representatives of marine fauna to his ear Some people believe that the noise coming from the sink is the sound of blood moving through the vessels of our body Others say that it is formed due to the movement of air currents inside the shell, twisted like a ram's horn Still others are sure that the splashing of the waves of the seas and oceans is heard because the noise of the environment resonates with the walls of the shell Thanks to this property, shells transmit vibrations and amplify sounds coming from outside Therefore, the louder the noise outside the shell of a mollusk, which acts as a resonator chamber of a stringed musical instrument, the stronger the sound of the sea surf produced by acoustic waves A scientific explanation destroys the mysterious veil that shrouds shells brought as souvenirs of a vacation on the coast Everyone who disagrees with this version and is in a romantic mood celebrates August 13th as the Day of Noisy Shells