Here's why...

• It is important to realize there are no "normal" animals born with only one ear. Simply stated, you have two ears because you need two ears. If you try to amplify sound in only one ear, you cannot expect to do very well. Even the best hearing aid will sound "flat" or "dull" when worn in only one ear.
• You need two ears to tell where the sound is coming from (localisation). Localisation is very important for determining the origin of warning signals, alerting sounds and of course, conversational speech.
• Using both ears together allows your central nervous system (your brain) to better focus on, and process sounds you want to hear (human speech) while more or less "squelching" (ignoring) sounds you do not want to hear (background noise). One ear working by itself cannot do this very well. The brain needs to compare and contrast loudness, pitch and the phase (timing) of the sounds from the two ears to make sense of it!
• It's sort of like using your eyes. If you close one eye, you cannot get depth perception. In other words, if you were to close one, it becomes very difficult to tell how far something is in front of you. It is also difficult to read and you'll find you get tired more quickly as you are straining and working harder to make visual sense of the world. Of course, if you had two eyes that were far sighted, or two eyes that were near sighted, you wouldn't even think about getting a monocle...and that would be analogous to wearing one hearing aid.

Assuming you have two ears that hear about the same, you can do a little experiment at home to better understand how important binaural hearing is:

• First, gently close just one ear, by simply pressing the little fleshy part in the front of your ear canal (the tragus) into your ear canal -- a little. Do not apply pressure, do not hurt yourself. Just close the ear canal to eliminate sound from entering the ear.
• Keep that ear closed for about ten minutes while you watch TV or listen to the radio or speak with your spouse.
• Then, after a full ten minutes, remove your finger.

Notice the difference?

Binaural hearing allows a quality of "spaciousness" or "high fidelity" to sounds, which cannot occur with monaural listening. Understanding speech clearly, particularly in challenging and noisy situations is much easier while using both ears. Additionally, using two hearing aids allows people to speak to you from either side – not just your "good" side!

People cannot hear well using only one ear. There are studies in the research literature that show that children with one normal ear and one "deaf" ear are ten times more likely to need to repeat an exam when compared to children with two normally hearing ears. Additionally, we know that if you have two ears with hearing impairment and you wear only one hearing aid, the unaided ear is likely to lose word recognition ability more quickly than the ear wearing the hearing aid.

The bottom line is ... if you have two ears that can benefit from hearing aids, fit both ears!