Do you think it's more difficult to guess physiological features from a voice or a voice from a picture?

I'm mostly deaf (cochlear implant) and one thing I've noticed is that if I watch things without my processor on (e.g., completely deaf), I can generally "guess" what a voice sounds like fairly accurately... I've wondered for a long time if it's a trick of my mind, a quirk of statistics, or something that's actually possible.