se oyó un

a … was heard

→ se
phrase Rare #40,518
a … was heard Used in an impersonal construction, typically before a masculine singular noun.
SP: De repente se oyó un golpe en la puerta.
EN: Suddenly, a knock was heard at the door.

Se oyó un chapuzón.

There was a splash.

Se oyó un disparo de francotirador desde cerca.

A sniper's shot was heard from nearby.

— Proyecto: El Internado (2026)

Se oyó un sonido en el dormitorio.

A sound was heard in the bedroom.