Yes.
We are born with two ears for a reason – to hear properly. Getting only one device is like wearing only one lens in your glasses: you’re able to see, but only to the side you’ve corrected.
The same thing applies to your hearing.
If you only fit one ear, you’ll only hear sound from that side of your head.
Sound from each ear travels into your brain and mixes before you process what you are hearing. Having proper sound on one side and muffled sound on the other will lead to improper understanding.
If you fit only one ear, how do you know which side to even fit? If you fit your left ear, for instance, and are driving your vehicle, you cannot be upset that you cannot understand your passenger! The right ear is facing the passenger while the left ear picks up road noises naturally.
If you can benefit from two devices, consider yourself lucky. People who have single sided deafness would love to be in your position.
Besides, when you’re fit, you won’t want to go with only one. You’ll see for yourself.