Westworld actor who suffered serious head injury revealed (Photo Credit: HBO/Rex Features)

TMZ has obtained the audio of Zahn McClarnon's call for help, which he placed on his own after he fell in his home and hit his head a couple weeks ago.

As you can tell, Zahn's clearly out of it during the convo with an operator. He comes off as confused when asked what apartment number he's in, but somehow manages to get out all relevant info needed for paramedics.

As we reported ... Zahn's injury temporarily halted production of season 2 of the HBO hit series, which was set to air in 2018.

The good news now ... HBO says filming has fully resumed.