All the Hindu temples have a bell at the entrance of the temple or inside the temple and usually, we need to ring it before we enter the temple and while doing pooja to god.
First, we must understand that a genuine bell is not made up of just ordinary metal.
It is made of various metals, which include cadmium, copper, lead, nickel, zinc, manganese and chromium.
The proportion at which each one of them mixed is real science behind a bell. Each of these bells is made to produce such a distinct sound that it can create unity of our left and right brain. when we ring that bell, bell produces a sharp but lasting sound which lasts for minimum of 7 seconds in echo mode, good enough to touch our seven healing centers or chakras in our body.
The moment bell sound happens, our brain is emptied of all thoughts. Invariably we enter a state of Trance state. The Trance state is the one with awareness.
In Kaliyuga, we are so occupied in mind that only way to awaken ourselves is "with a shock" and Bell works as an anti-dote to our mind.
Bell or ghanta is an indispensable part in most Hindu pujas. Bell is sounded before the actual puja and worship begin. A well designed Bell produce long strains of the sound "OM".
The body of the bell represents time - "Ananta".
The tongue of the bell represents Goddess "Saraswati".
The handle of the bell is considered to be the viral principle (prana sakti) and represents Hanuman, Garuda, Nandi or Charkra.
even while doing the Aarti, we ring the bell. It is sometimes accompanied by the auspicious sounds of the couch and other musical instruments.
An added significance of ringing bell, conch and others instruments is that they help down any inauspicious or irrelevant noises and comments that might disturb or distract the worshippers in their devotional adrour, concentration and inner peace.
"So, next time you visit a temple just think about it"
