Check the Mute Setting
Make sure the audio system isn't muted. Try pressing the Mute button on the dashboard or steering wheel and see if that restores sound.
Volume Control
Turn the volume knob both ways to ensure it’s not stuck at 0. Sometimes the knob may need to be pressed or turned repeatedly to reset it.
Check the Audio Source
Ensure that the correct audio source (radio, Bluetooth, USB, etc.) is selected. Try switching between sources to see if one has sound.
Settings
Go into the vehicle's Settings menu and check the audio settings. Resetting the audio preferences to default can sometimes resolve unexpected issues.
Vehicle Restart
Turn the engine off, exit the vehicle, and lock it. Wait a minute or two, then unlock and start the vehicle again to see if that resets the system.
Check for Software Updates
If you have a connected smartphone, check if there are any software updates available for the infotainment system via the Toyota app. Updates can fix bugs related to the audio system.
Disconnect the Battery
If none of the above works, you may want to disconnect the vehicle battery for 10-15 minutes to reset the system. Be sure to have the vehicle in a safe location with the engine off when doing this.
If none of this works, you might want to reach out to your local dealer.