Shank comes from the two Sanskrit words "Shum" which means something good and "Kham" meaning water. Hence the meaning of Shankam is conch holding the sacred water. It is also said word Shankara was been derived from Sankha-kara which means conch-blower (shankha means conch and  Kara means  blower).

When the conch is blown with controlled breath, the primordial sound of "Om" emanates from it. This eternal sound is 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.

 The blowing of a conch shell enhances the positive psychological vibrations such as courage, determination, hope, optimism, willpower  and bliss can be felt by  all people assembled and also by the blower.