When a photo is taken, a camera sound is heard as an acoustic confirmation that a photo has been taken. By default, the camera sound is activated on the Oppo Smartphone, but can be deactivated in the settings of the camera app.

Android 10 | ColorOS 7.0
Step 1:  Open the  Camera-App
Step 2:  Open the  Menu
Step 3:  Open the  Settings
Step 4:  Enable or Disable  Shutter Sound
  1. Open the Camera-App
  2. Open the Menu
  3. Open the Settings
  4. Enable or Disable Shutter Sound

Oppo Instructions