The reason we have two ears is to facilitate the knowledge of the environment. That is, thanks to the small difference (from thousands of milliseconds) in the time it takes a sound to an ear and then to the other, the brain is able to calculate the orientation of the sound source.
People who adapt a single hearing aid lose this information. Then, they should help with the vision.
Hearing aid manufacturers have been incorporating technologies to improve coordination between the two devices. The near field magnetic induction is the newest. It allows an information exchange of up to 21 times per second with a minimum energy consumption.
The result is an improved binaurality, giving the hearing aids a natural and comfortable experience.