Amazingly Funny Goof!*2008 state of the art hearing aid.

I just saw this movie. Knowing id be looking at a b-rate movie i naturally expected som flaws. However at 37,20 min in the movie my jaw dropped to the ground:) Thurman Prescott(old dude) turns sideways and as clear as day theres a year 2008 state of the art hearing aid device connected in his left ear!:) - now hows that for a concept in a western that (i suppose) was ment to look like taking place a 100 - 150 years ago?