If you want to hear audio when live-streaming the camera, check below to turn on the audio for your camera.

Applies to: All Reolink cameras

Here are some guides for your reference.

How to Turn on Audio on Camera Live View on Reolink app

How to Turn on/off Audio in Live View via Reolink Client (New Client)

How to Turn on Audio on Camera Live View on PoE NVR

How to Turn on Audio on Cameras Live View on PoE NVR(New UI)