Why do we ring the bell?

 

In most of the temples there are one or more bells hung from the top, near the entrance. The devotee rings the bell as soon as he enters, thereafter proceeding for darshan of the lord and prayers. Children love jumping up or being carried high in order to reach the bell. 

Why do we ring the bell?
Is it to wake up the lord ? But the lordnever sleeps. Is it to let the lord know we have come?  He is all-knowing. Is it a form of seeking permission to enter his precinct? It is a homecoming and therefore entry needs no permission .  The lord welcomes us at all times. Then what would be the reason for this?
The ringing of the bell produces what is regarded as an auspicious sound. It produces the sound of om, the universal name of the lord. There should be auspiciousness within and without, to gain the vision of the lord who is all-auspiciousness.
Even while doing the ritualistic aarati, we ring the bell. It is sometimes accompanied by the auspicious sounds of the conch  (shank) and other musical instruments. An added significance of ringing the bell or conch is that they help drowned any inauspicious or irrelevant noises and comments that might disturb or distract the worshippers in their devotional ardour, concentration and inner peace.
As we start the daily ritualistic worship (pooja) we ring the bell, chanting:
         Aagamaarthamtu devaanaam
               Gamanaarthamtu rakshasaam
       Kurve ghantaaravam tatra
                   Devataahvaahna lakshanam.
(Source: book-in Indian culture why do we........by Swamini Vimalananda & Radika Krishnakumar)
  Meaning--  I ring this bell indicating
         the invocation of divinity,
                So that virtuous and noble           forces enter ( my home and heart);
     And the demonic and evil forces
     From within and without, depart.