Questions & Answers about Yo escucho en silencio cuando hablan los demás.
In Spanish you do not need to say the subject pronoun most of the time, because the verb ending already shows who the subject is.
- Yo escucho = I listen
- Escucho (without yo) also means I listen.
In your sentence:
Both are grammatically correct.
Using yo adds a bit of emphasis, like:
- I (as opposed to others) listen in silence when others speak.
In everyday Latin American Spanish, people often drop yo unless they want to emphasize it or avoid ambiguity.