When a drum is empty, there's more air inside which can vibrate freely, resulting in a louder sound. This science phenomenon is applid to those has little substance tend to be the most vocal. This theory can be applied in real life and proven a lot of times. Our ancient Sanskrit has given the following verses to explain the same :
उत्तमो नातिवक्ता स्यात् मध्यमो बहु भाषते
न काञ्चन ध्वनिस्तादृक् यादृक् कांस्य प्रजायते.
Uttamo naativaktaa syaat madhyamo bahu bhashate,
Na kaanchan dhwanistaadruk yaadruk kaansya prajaayate.
Uttam = Best. (here reference is to honourable persons)
Naati vaktaa = na + ati + vaktaa
Na = not.
Ati = too much.
Vaktaa = 0ne who is speaking.
Syaat = are.
Madhyam = middle
Bahu = too much.
Bhaashate = speak, talk.
Kaanchan = gold.
Dhwani = sound .
Taadruk = like that of.
Yaadruk = like this.
Kansya = bronze, an alloy of tin and copper used for making bells, as it produces loud sound compared to Gold, which produces only a thud, bronze (a base metal) produces a loud sound.
Prajayate = produces.
Honourable persons never indulge in loose talks whereas ordinary persons talk too much unnecessarily, just as Gold (considered as best and costliest metal) does not produce a loud sound like bronze (a base metal) on being struck.
This is an important phrases which implies that knowledgeable persons do not indulge in unnecessary and loose talk, whereas those who are less knowledgeable are always talkative. It signifies that those who lack real understanding tend to be the most vocal, while those with true knowledge often speak less and with more weight. This applies in life when someone with limited expertise tries to dominate a conversation or boast excessively to compensate for their lack of depth.
The proverb encourages us to be mindful in a group discussion and talk sensibly. Value individuals who speak with thoughtful consideration and demonstrate genuine understanding.
@queenart