If your PVO projector has no sound, then you can try the following solutions.
Please make sure that your PVO projector has a built-in speaker first. If not, you need to connect the projector to an external speaker.
Check whether the PVO projector is muted. Press the Mute or volume setting button on the remote or the projector panel.
When connecting a computer to a PVO projector, no sound will be output unless the computer recognizes that the sound outputs from the projector. You can open the audio Settings on your computer and change the output source to your PVO projector.
When connected to a Blu-ray /DVD player, the projector may have no sound depending on the audio output Settings. Open the Settings on the connected player and change the digital audio output to PCM.
Some copyrighted content can’t be mirrored via smartphone and won’t produce sound.
You may be interested in How to Connect PVO Projector to iPhone.
Turn off Dolby sound when streaming content on some apps like Netflix as the PVO projector does not support the audio format.
When connecting the PVO projector to a TV box, you can try to adjust sound using the remote of the TV box instead of the projector’s remote.
Make sure the connection cable is properly connected when connecting it to external speakers.