I've tried yelling "On your right" or "On your left" to let people know which side I'm going to pass on but it doesn't work like in mountain biking. Most people just think you're being a dick and get mad, or they're wearing headphones and can't hear me, or have no idea what it means and turn IN the direction I say instead of AWAY.
People will look to where the noise is coming from. The body follows the head so they will turn in that direction.