I know this thread was started related to the Cros hearing aid, but I did want to comment on Paul's reply on the "head shadow" effect. The bone-anchored hearing devices also eliminate the head shadow effect.
I have an Oticon Ponto Pro bone-anchored hearing device and I am one of the ones who has recovered some directionality. My audiologist explained that hearing is a function of the brain ..... the ears are simply the vehicle transmitting sound to the brain. Sound from the right ear goes to the left hemisphere. Sound from the left ear goes to the right hemisphere and then back to the left hemisphere for language processing. I am SSD on the left so I have no longer have sound input going to the right hemisphere. However, the language center in the left hemisphere of my brain has apparently learned to distinguish the sounds coming from the processor through my only auditory nerve, from those of my normal hearing through that nerve. Most of the time I turn in the correct direction upon hearing a sound ..... especially voices.
I am very aware that many Ponto or BAHA users do not regain directionality, but it can happen. My audiologist feels like the shorter the time a person is SSD, the greater the possibility of achieving success in directionality. Also, I think my years of being a classically-trained musician has probably fine-tuned my hearing more than someone else might.
All this is to say, I would think with any hearing device directionality is a possibility. I went in to surgery not expecting to have any directionality with the Ponto and have been pleasantly surprised.
Clarice