A conch is a sea-dwelling mollusc. In Hindu religion, it is popularly
called as "Shankha" and considered to be one of the
most auspicious objects that emerged from the sea during the Ksheera
Sagara Samudra Manthan. Religious Significance
In Indian mythology, the Shankha is regarded sacred and very auspicious. To initiate religious ceremonies, a shankha (conch shell) is blown. It is a major Hindu article of prayer. God Vishnu, the God of Preservation, is shown with a shankha in one hand and a disc or a chakra in the other.
Each hindu shankha has a specific name. Vishnu's shankha is called "Panchajanya". It is believed that when it is blown, it announces the victory of good over evil. In the epic war, Mahabharata, the conch shell held a significant place. Arjuna's shankha was called "Devdutta", Bhima's "Paundra", Yudhisthira's "Anantavijaya", Nakula's "Sughosa" and Sahadeva's was known as "Manipushpaka".
The sacred conch shell is an integral part of Hindu symbolic and religious tradition. Even today, all Hindus use the conch as a part of their religious practices. Whenever the conch shell is blown, it is said to purify the environment from all evil effects.
Scientific significance
Leaving aside the mythology part, the conch shell's significance can also be corroborated by science. If you try holding a shankha near your ear, the sound of the gently humming ocean can be heard. This is actually the natural vibration or cosmic energy of the Earth which gets magnified on entering the conch shell.
The vibrations from these conch shells can overpower evil forces from the Earth and at the same time also clear environmental pollution including healing the hole in the ozone layer which causes global warming. According to science, the blowing of a conch shell enhances the positive psychological vibrations such as courage, determination, hope, optimism, willpower, etc. in the blower as well as those around him.