Just a few days after the launch of the OnePlus 8 series, OnePlus is rolling out the first software update for the devices. The day 1 update for the OnePlus 8 series adds features like Live Caption support, Dolby Atmos integration for the newly launched Bullets Wireless Z, Android security patches for March 2020, and more. Since the devices are yet to go on sale, users can expect to receive this update as soon as they set up their new OnePlus 8 (review) or OnePlus 8 Pro (review).

OnePlus 8 XDA Forums || OnePlus 8 Pro XDA Forums

The day 1 OxygenOS update for the OnePlus 8 series goes by the build number 10.5.1 for the OnePlus 8 EU variant, OxygenOS 10.5.3 for the OnePlus 8 international variant, OxygenOS 10.5.2 for the OnePlus 8 Pro EU variant, and OxygenOS 10.5.4 for the OnePlus 8 Pro international variant. Here's the complete changelog for the first OnePlus 8 series update:

  • System Updates
    • Improved icon display in status bar
    • Improved back gesture experience
    • OnePlus Bullets Wireless Z can now be integrated with Dolby Atmos for better sound quality
    • Added double-tap feature to wake up lockscreen in ambient display more or off-screen condition
    • Added OnePlus Tips & Support section in Settings. Check out all the new features and answers to common issues here
    • Added Live Caption, this will detect speech in media and automatically generate caption [To enable: Settings-System-Accessibility-LiveCaption]
    • Updated Android Security Patch to 2020.03
    • Updated GMS package to 2020.02
  • Camera Updates
    • Optimized the camera's shooting experience and improved stability
    • Optimized the animation effect and improved interaction experience
    • Added video filter feature
  • Phone Updates
    • Added contact notes info for incoming calls
  • Network Updates
    • Enabled 3 UK 5G
    • Enabled Sweden Tele2 VoWiFi
    • Enabled T-Mobile Australia VoWiFi and 5G
    • Optimized network data transmission performance and stability
  • Voice Assistant Updates
    • Now you can wake up voice assistant of your choice just by long-pressing the power button [To enable: Settings-Buttons & gestures-Press and hold the power button-Choose the app you want to activate]

Thanks to XDA Senior Member Some_Random_Username for the tip!