The shankha (conch-shell) is regarded sacred and auspicious in the Indian system. Like the swastika
symbol [c.f. Akhand Jyoti Jan-Feb 2005], it is an integral part of Vedic sacraments. It is blown to initiate religious ceremonies. God Vishnu is shown with a shankha in one hand and a disc (chakra) in the other. In the battlefield (Kurukshetra) of Mahabharata, Lord Krishna is said to have wielded a mighty shankha called the ’Panchajanya’. It is believed that when it is blown it announces the victory of good over evil.
Using tremendous lung-power, stamina and sustained breath control the player blows air into the shell to produce a powerful resounding reverberation that is deemed to match with the primal sound of creation. While the shankha has but one note, by controlling the breath, the player can alter the magnitude, timbre and resonance of the note. Though it does not have much application as a musical instrument, the vibrant, sonorous sound of shankha inspires valor, courage, enthusiasm and inner spirit. The holy Gurbani of the Sikhs also recognizes these effects as "Sankhan ki dhun ghantan ki kar phulan ki barkha barkhavae ...". (The conch and the bell produce blissful sounds…).
An adept yogi is said to subliminally hear the shankhanada (sound of perfect blowing of a shankha), within himself during the higher stages of trance in Nadayoga Sadhana. When the conch is blown with controlled breath, the primordial sound of "Om" (Oam) emanates from it. This eternal sound is said to be the origin of all Vedas. All knowledge enshrined in the Vedas is an elaboration of the omnipresent sublime sound of Om. It was this sound that was chanted by the Lord before manifesting the cosmos. It represents the creation and the Truth
behind it. It represents dharma or righteousness that is one of the four noble goals of human life.
As per the scholarly analysis of Shastric terminology, that which leads to welfare is called "shankha". It is with the sounding of conch that the doors of temples are opened. Another well-known purpose of blowing the conch with or without some devotional instruments, known traditionally to produce auspicious sounds, is to ward off negative vibrations or noises that may disturb the ambience or the minds of the devotees.
Some German scientists are reported (http://mailerindia.com/ hindu/veda) to have experimented on conch shell’s sound and found that diseases like those of thyroid and some other hormonal disorders are healed or significantly cured by this sound. Surprisingly the sound waves generated by collective blowing of shankhas are also believed to prevent spread of plague, cholera etc in the surroundings. This indicates the existence of an advanced knowledge and scientific use of sound in Vedic India.
In ancient India, each village was presided over by a main temple deity and several smaller ones. During performing the Aarti (devotional prayer-song after pooja worship) and before and after all the important sacraments and on sacred occasions, the blowing of conch was a must. Since villages were generally small, the sound of the conch would be heard all over the village. People who could not make it to the temple were enjoined to stop their work, at least for a few seconds, and mentally bow to the Lord. The conch sound served to awaken people’s minds to a prayerful attitude even in the middle of their busy daily routine.
The shankha is placed at the altar in temples and homes next to the Lord as a symbol of Nada-Brahma, Om, the Vedas, Dharma, righteous victory and auspiciousness. It is often used to offer devotees sanctified water (of sacred oblation) to uplift and focus their minds towards nobility and truth.
Like the pyramids, the specific geometry of a shankha generates remarkable energy-effects. More remarkable is the fact that these are formed naturally. Different kinds of shankhas are therefore used as yantras for different purposes in the mantra- and tantra- based sadhanas. Some adept astrologers also recommend the types of shankha and the location where these are to be placed to control negative planetary effects. Several kinds of methods of worshipping the shankhas are also described in the Indian scriptures for benefits varying from wealth, success and peace of mind to health, healing and hypnotism.