My school teacher always talk about "empty drums noise much". The is a proverb "empty vessels make the most noise" means that people who claim to be knowledgeable, talented, or experienced are often not as knowledgeable, talented, or experienced as they say. The opposite of this proverb is "still waters run deep". A knowledgeable person might not talk much. As people gain more wisdom and insight, they may become more selective about what and when they say.
I think this is a good sign to identify a knowldgeable person. This is something keeps them apart from others. We have a similar verses popular in Sanskrit which states the same meaning. It goes like :
उत्तमो नातिवक्ता स्यात् अधमो बहु भाषते|
न कान्चेन ध्वनिस्तादृक यादृक् कांस्ये प्रजायते||
Uttamo naativaktaa syaat adhamo bahu bhaashate.
Na kaanchena dhwanistaadruk yaadruk kaamsyo prajaayate.
Uttamo = great people.
Naativaaktaa = Na + ativaktaa.
Na = not.
Ativaktaa = talkative, garrulous.
Syaat = perhaps
Adhamo = inferior and vile people.
Bahu = too much.
Bhaashate = talk.
Kaanchena = gold's.
Dhwanistaadruk = dwhanih + taadruk.
Dhwanih = sound.
Taadruk = in such a manner.
Yaadruk = like that of.
Kaansye = bronze , brass or bell metal.
Prajaayate = generates.
the lines imparts the following meaning : Honorable persons are generally not talkative, whereas ordinary and lowly persons are very talkative, in the same manner as Gold (being a precious metal), on being hit produces a muted sound as against a loud sound produced by brass or gunmetal (which is cheaper)
In these lines the honourable and righteous persons are compared to Gold and ordinary persons to brass or gunmetal, taking a cue from the sound produced by these metals and their relative qualities.