As the old saying goes, 2 heads are better than one and we could keep going with 2 hands, 2 legs, 2 eyes, 2 ears are better than 1, etc., etc.
But what are the actual advantages?
The hearing becomes much more natural with sounds coming from all around you.
Being able to identify where the sound is coming from is only possible with 2 aids. Eg. which direction is a car or bus coming from when you are out and about in the street.
It is twice as easy to understand the words when others are speaking.
It enables you to participate in conversations when there is noise around you.
The unaided ear tends to lose its ability to hear and understand over time. Both ears needs to be kept active.
Hearing is less tiring and listening more pleasant.
Wider hearing range
A voice that’s barely heard at 3 meters with one ear can be heard up to 12 meters with two ears.
Listening to loud sounds