Shankham" comes from the two Sanskrit words "Shum" which means something good and the "Kham" meaning water. Hence the meaning of "Shankam" is "The conch holding the sacred water".
As the story goes, the demon Shankhaasura defeated devas, the Vedas and went to the bottom of the ocean. The devas appealed to Lord Vishnu for help. He incarnated as Matsya Avataara - the "fish incarnation" and killed Shankhaasura. The Lord blew the conch-shaped bone of his ear and head. The Om sound emanated, from which emerged the Vedas.
All knowledge enshrined in the Vedas is an elaboration of Om. The conch therefore is known as shankha after Shankaasua. The conch blown by the Lord is called Paanchajanya. He carries it at all times in one of His four hands.
It represents dharma or righteousness that is one of the four goals (purushaarthas) of life. The sound of the conch is thus also the victory call of good over evil.
The Shanka verse recited in pooja is:
"Shankham chandrakadaivatwam kukshouvaruna daivatam
prusthe prajapatirdaiva mugre ganga saraswati
Pruthivyam yani teerthani vasudevasyachagyaya
Shankhe tisthanti viprendra tasmat shankham prapoojyayet"
The conch-shell is said to be the preserve of several gods and goddesses: Brahma on the seat (shankhapitha or shankhadhara), Surya in the middle and Chandra at the tip. On the right side are seated Aditya, varuna, Soma, Vayu and Agni. Shankha is presided over by the twin gods Sun and Moon, and Varuna is it’s deity; at the back of the conch-shell is Prajapati, and in front the river goddesses Ganga and Sarasvati. So even to look at a conch-shell, or to touch it, would mean eradication of sins, like darkness disappearing on sunrise. The shankha is one of the four attributes that Vishnu holds in his hands. Hence the Shankha should be worshiped. According to Tantric belief, the shankha keeps away evil spirits and saves one from calamities.
According to Tantric belief, the shankha keeps away evil spirits and saves one from calamities.
"Shankha Madyesthitam Thoyam Brahma Hatyadhikam Daheth
Anga Lagnam Manushyanam Mruthyu Samsara Bheshajam"
The water from the Shankha purifies the sinner and can cure all the ailments which cannot be cured by the other medicines. It is a cure for the physical ailments in humans, from the the fear of death and gives liberation from the eternal cycle of birth and death. Shankha powder is used in several Ayurvedic medicines.
Mythologically speaking there are Six main types of Shankh:
Vamavarti Shankha, Dakshinavarti Shankha, Ganesha shankha, Gaumukhi Shankha, Kauri Shankha, Moti Shankha.
Correct method of blowing shankh
Blowing of shankh the frequencies consisting raja-tama particles are destroyed and at the same time the saviour and destroyer principle of a deity is awakened. Now let us see the correct method of blowing the shankh.
First slightly raise your neck and bend it little backwards and keep the mind focused. Take a deep breath and start to blow with increasing intensity. One should keep in mind that blowing of shankh should be completed in one single breath. When the shankh is blown in this way Sushumna channel of the individual gets activated and it helps in keeping a correct balance of raja and sattva particles related to Tej and Vayu elements. This awakens the saviour and destroyer principle of adeity according to the need.
Why should the person blowing the conch raise his neck?
The person blowing the conch should raise his neck upwards (towards God) and fully concentrate on the task at hand. When blowing the conch, the eyes should be closed and a spiritual emotion should be nurtured that one is beckoning the subtler frequencies of the unmanifest, destroyer form of God'. This posture activates the Sushumnanadi (Central Channel) in the body of the conch-blower. It also helps in maintaining a perfect balance between the raja-tama particles in the frequencies related to the absolute air and absolute fire elements that emanate from the mouth. Thus, as per the requirement - the saviour and destroyer principles of the Deity get activated.
When blowing the conch, close the eyes and cultivate a bhav that the marak (destroyer) frequencies of the unmanifest form of God are being received from above.
Blowing of the conch in a single breath: As far as possible, take a deep breath and fill the lungs with air, and then blow the conch in a single breath. This way the resonance of the vibrations (the resonance of subtle sound in the environment) lasts for a longer period. Due to the strength of the sound vibrations in the resonance, it becomes possible to tear apart the black covering surrounding the aerial body of the negative energies in the vicinity in a short time.
The sound of the conch should go from a low to a high pitch: When blowing the conch, the sound should start from a low and go to a high pitch which should be maintained till the conch-blower stops.
Manifestation of negative energies due to the sound of the conch: Due to the sound energy generated by blowing the conch, subtler frequencies flowing down from the universe get activated. They cause disintegration of raja-tama particles in the atmosphere within a short time. Due to the momentum of frequencies of sound energy emanating from the conch, there is friction between raja–tama particles, resulting in subtle flames. As a result the sheath around the aerial bodies of negative energies starts to burn. That is why negative energies are unable to tolerate the sound of a conch. They are compelled to manifest because of this sound. However, some of the more powerful sorcerers from the negative subtle region pretend to be unaffected, despite the distress caused by the sound of the conch!
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. Following type of Shankhas are considered very sacred and pure in Hinduism