If you have hearing loss in both ears, and if both ears can benefit from hearing aids, then it's more likely that you will hear much better with two hearing aids.
It's important to realize that there are no "normal" animals born with only one ear. Animals - and humans - have two ears because we need two ears. If you try to amplify sound in only one ear, you should not expect to hear very well. Even the best hearing aids will sound "flat" or "dull" if worn in only one ear.