Why do we ring the bell in a temple?
Because there are so many thoughts wandering in your mind, with the sound of the bells you come into the present. Your thoughts come to a halt.
The drummers beat large drums, play the Naadaswaram, shehnai, bells, and conch. All these sounds are made so that your mind becomes quieter.
Your mind is like a kid. When a kid is crying, you cry louder than the kid and the kid becomes quiet. Have you noticed that? In the same way, when there is so much noise in your mind and too many thoughts, they blow the conch, ring the bell and with all the sounds, the mind comes to the present moment.
With so much noise around, the mind cannot think. It cannot wander. So it is used as a technique.
All outside sounds suppress the sound of the mind for a little while. This short-term suppression should lead the mind to silence. Once it goes into the depths of meditation, all words feel burdensome. But when the mind is full of words, and you are troubled by too many thoughts, these sounds bring relief. Have you seen in the Buddhist monastery, there is a big gong? They ring the gong and that vibration will keep you silent. So, from sound to silence, the journey is very important.