For many individuals, the prospect of being fitted with two hearing aids may be daunting. Often new hearing aid users may feel that the process of adjustment with a single aid may be easier than two, more cosmetically appealing or in some cases it may be financially difficult to purchase two hearing aids. If a hearing loss is present in both ears, it would be recommended that you wear a hearing aid in each as the expected benefit of wearing two hearing aids exceeds that of wearing one. To totally understand the benefit of wearing two hearing aids we need to recognise that the process of hearing is not limited to only our ears but also involves the brain. Much of our brain's ability to make sense of sound is based on the information it receives from both ears working together. A few reasons why two hearing aids are recommended over wearing one:

1. Better hearing in noise - Hearing speech in noise can be improved if the sound reaching each ear arrives at slightly different moment in time - this time difference helps the brain process a signal more efficiently.

2. An improved ability to tell what direction sound is coming from (sound localisation) - the brain uses the sound entering each ear to determine the direction of the sound.

3. Wearing two hearing aids gives you a more natural balance of sound.

4. Less listening effort is required to be able to understand speech in noise.
5. Individuals fitted with two hearing aids are more satisfied than those fitted with one.

Second Answer: Two hearing aids (binaural) is usually best for a patients ability to hear well. There are a few exceptions. I recommend only one hearing aid (monaural) for patients in these situations: 1) One ear has normal hearing. This ear would not need an aid. 2) One ear is completely deaf and cannot be helped with an aid. 3) The patient absolutely cannot afford a second aid. One is better than none but two would be best. I like to give this handout to patients that question me when I recommend two hearing aids for them and they insist that they only need one. Do I need one hearing aid or two? If you have hearing loss in both ears it is best to have two hearing aids. Here are the reasons why:

1.) Better reception of sounds and soft spoken words. To approximate the performance of two aids, a single aid may have to be worn with the volume at a higher volume than it would if two aids were worn. The higher volume setting puts the patient closer to the point beyond which an increase in sound level becomes uncomfortable or painfully loud. The addition of the second aid can have the effect of increasing the range of sound pressure than the patient can comfortably wear.

2.) Better understanding of speech in background noise. Even a person who has one normal ear and one non- functioning ear has trouble with understanding speech in the presence of noise. In order for the central nervous system to "sort out" speech from noise, input from both sides of the head is required.

3.) Reception of sound from both sides of the head. The addition of a second aid reduces the need of rotating the head around to face the speaker, making communication easier and more comfortable.

4.) Localization of the sound source. The ability to localize the origin of a sound allows a person to react more appropriately to his/her environment. It also helps with acoustic balance.

Two hearing aids are not recommended for all patients evaluated. When the recommendation is made, it is because the hearing health-care provider feels that the communicative abilities of the patient will be significantly improved by wearing two hearing aids instead of one. Typically I find that I can prove to the patient that their ability to understand speech is better with both ears than one ear alone on their word discrimination test.