Kochkin's article on the satisfaction of binaural hearing aid wearers over monaual. It's not referenced, but most of the points derived are common with Mead Killion's work which derived from the directional studies by Peter Madaffari et al in the early 1980s.
Sergei Kochkin, Ph.D. - Better Hearing Institute, Washington, DC
If you have hearing loss in both ears (bilateral hearing loss), then you are most likely a candidate for two hearing aids, which is called binaural hearing aids. While a hearing healthcare professional can best determine if you are a candidate for two hearing aids, the ultimate decision-maker concerning binaural instruments is the person who will wear them. It is important that the person with the hearing loss be given the chance to experience binaural hearing aid amplification before a decision on one or two hearing aids is made. Similar to the way refractory problems in both eyes are treated with a pair of glasses, it makes sense that bilateral hearing loss should be treated with binaural hearing aids. Let me share with you why two hearing aids are better than one.
Better understanding of speech. By wearing two hearing aids rather than one, selective listening is more easily achieved. This means your brain can focus on the conversation you want to hear. Research shows that people wearing two hearing aids routinely understand speech and conversation significantly better than people wearing one hearing aid.
Better understanding in group and noisy situations. Speech intelligibility is improved in difficult listening situations when wearing two hearing aids.
Better ability to tell the direction of sound. This is called localization. In a social gathering, for example, localization allows you to hear from which direction someone is speaking to you. Also, localization helps you determine from which direction traffic is coming or where your children or grandchildren are playing. Simply put, with binaural hearing, you will better detect where sounds are coming from in every situation.
Better sound quality. When you listen to a stereo system, you use both speakers to get the smoothest, sharpest, most natural sound quality. The same can be said of hearing aids. By wearing two hearing aids, you increase your hearing range from 180 degrees reception with just one instrument, to 360 degrees. This greater range provides a better sense of balance and sound quality.
Smoother tone quality. Wearing two hearing aids generally requires less volume than one. The need for less volume results in less distortion and better reproduction of amplified sounds.
Wider hearing range. A person can hear sounds from a further distance with two ears, rather than just one. A voice that's barely heard at 10 feet with one ear can be heard up to 40 feet with two ears.
Better sound identification. Often, with just one hearing aid, many noises and words sound alike. But with two hearing aids, as with two ears, sounds are more easily distinguishable.
Keeps both ears active resulting in potentially less hearing loss deterioration. Research has shown that when only one hearing aid is worn, the unaided ear tends to lose its ability to hear and understand. This is clinically called the auditory deprivation effect. Wearing two hearing aids keeps both ears active.
Hearing is less tiring and listening more pleasant. More binaural hearing aid wearers report that listening and participating in conversation is more enjoyable with two instruments, instead of just one. This is because they do not have to strain to hear with the better ear. Thus, binaural hearing can help make life more relaxing.
Feeling of balanced hearing. Two-eared hearing results in a feeling of balanced reception of sound, also known as the stereo effect, whereas monaural hearing creates an unusual feeling of sounds being heard in one ear.
Greater comfort when loud noises occur. A lower volume control setting is required with two hearing aids than is required with one hearing aid. The result is a better tolerance of loud sounds.
Reduced feedback and whistling. With a lower volume control setting the chances of hearing aid feedback is reduced.
Tinnitus Masking. About 50% of people with ringing in their ears report improvement when wearing hearing aids. If a person with tinnitus wears a hearing aid in only one ear, there will still be ringing in the ear that does not have a hearing aid.
Consumer preference. An overwhelming majority of consumers who have hearing loss in both ears, choose two hearing aids over one, when given the choice to hear binaurally.
Customer satisfaction. Research with more than 5,000 consumers with hearing loss in both ears demonstrated that binaurally fit subjects are more satisfied than people fit with one hearing aid.
Logically, just as you use both eyes to see clearly, you need two healthy ears to hear clearly. Before you decide on one hearing aid, try two. Your hearing healthcare professional can demonstrate to you the binaural advantage experience either through headphones (during testing), probe microphones, master hearing aids, or during your trial fitting. Decide for yourself.