hyogwa-eumi mudae dwieseo deullyeo.

The sound effect can be heard from backstage.

Breakdown of hyogwa-eumi mudae dwieseo deullyeo.

• 들리다: to be heard
• 무대 뒤: the backstage area
• 효과음: the sound effect

Questions & Answers about hyogwa-eumi mudae dwieseo deullyeo.

Why is the verb 들려, not 듣다?

Because 들려 comes from 들리다, not 듣다.

• 듣다 = to listen / to hear in the sense of actively hearing something
• 들리다 = to be heard / to come through audibly

In this sentence, the idea is not really someone is intentionally listening. It is more like:

• A sound effect is audible
• A sound effect can be heard
• I hear a sound effect

So 효과음이 무대 뒤에서 들려 sounds natural because the sound is simply reaching the listener.

Compare:

• 효과음을 들어 = (I) listen to the sound effect or hear the sound effect
  This treats 효과음 as the object.
• 효과음이 들려 = The sound effect is heard / I can hear the sound effect
  This treats 효과음 as the thing that becomes audible.

How is 들려 formed?