Understanding Hearing Loss
To Your Health -- CHRC Newsletter
Last Reviewed April 2003
Brad Hinrichs, M.D., PAMF Ear, Nose & Throat
More than 28 million people in the United States have a significant loss of hearing. Almost half of these individuals are under the age of 65, and 54% of the population over 65 years of age have hearing loss. Hearing loss is the third most prevalent chronic health condition in the older population, following arthritis and high blood pressure.
The impact of hearing loss can be far reaching and involve many different aspects of one's life. Hearing impaired individuals may have difficulty localizing sounds, understanding speech in noisy environments, and contributing to conversations. This can lead to social isolation, confusion, frustration, tension, stress and depression. There is mounting evidence that untreated hearing loss has enormous impact on the overall health of individuals.
What is normal vs. impaired hearing?
To answer this question, you must first understand how the human ear works. Sound travels in air-conducted waves to your outer ear, or pinna, and is funneled into the ear canal where it strikes the ear drum causing it to vibrate. The vibrating motion of the ear drum is translated into movement of the three bones of the middle ear - the malleus, incus, and stapes. Together with the ear drum, these three bones magnify sound pressure waves 22 times and deliver this energy to the inner ear fluids. Thus, air waves are converted to fluid waves in an efficient manner, and tiny hair cells within the inner ear send neural impulses via the auditory nerve and brain stem to the auditory cortex in the brain for interpretation.
Hearing loss results when there is an interruption in the path of sound through the air to the brain.
Conductive hearing loss occurs when there is a problem in the outer ear or the middle ear, such as excessive ear wax, fluid behind the ear drum, or a middle ear infection. This type of hearing loss is usually reversible with medical or surgical treatments.
Sensorineural hearing loss occurs when there is a problem in the inner ear or along the auditory nerve, and can be caused by severe infections, toxic medications, genetic errors, excessive noise exposure, or the aging process. Sensorineural hearing loss is usually permanent and irreversible.
How is hearing loss classified?
Hearing loss is generally described as mild, moderate, severe, or profound. A mild hearing loss may cause you to miss 25% of the speech signal and usually manifests itself as a subtle loss in clarity of one's hearing. A moderate loss has a more significant impact on understanding of speech. You might have little trouble in a good acoustic environment, face to face with someone who speaks up and articulates. However, in a noisy environment such as a restaurant or cocktail party, especially if visual cues are less available, someone with moderate hearing loss will have increasing difficulty understanding sentences and contributing meaningfully to conversations. Severe hearing loss may completely disrupt speech understanding even in the best acoustic setting.
Another factor to consider when classifying hearing loss is the location of the hearing loss across the range of speech frequencies. Usually a hearing loss does not affect all frequencies the same. Frequently people will present to their doctor or audiologist with high- frequency loss, common with the aging process (presbycusis) or excessive noise exposure. Others may have predominantly low-or mid- frequency losses which affect speech understanding in different ways.
Symptoms of hearing loss
When our hearing starts to fade we tend to forget how things sound. We begin to live in a quieter world, often unaware that we are missing the softer sounds of everyday life- like the patter of rainfall, the sound of birds singing, our children's and grandchildren's whispers; the very sounds that enrich our lives. The most common complaint from someone with hearing loss is "I can hear, but I cannot understand." This is because hearing loss leads to three kinds of communication challenges.
It might be time to consult with a hearing specialist if you are experiencing one or more of the following:
- People seem to be mumbling a lot.
- You have to strain to listen when spoken to.
- You have difficulty hearing someone call you from another room.
- Following a conversation is difficult, especially in a noisy setting.
- You have to turn up the volume of the TV or stereo.
- You have problems hearing clearly on the telephone.
- You have problems hearing clearly at lectures, meetings, or the theater.
- You have begun to limit your social activities.
- Family or friends mention that they often have to repeat themselves.
A family guide to hearing loss and rehabilitation
Hearing usually deteriorates very gradually - it may occur so slowly that the affected individual isn't even aware of the problem. The hearing impaired individual might exhibit some subtle personality shifts, asking others to repeat themselves, speaking more loudly, turning up the TV or stereo, seeming more tense or angry, or even becoming slightly sad and depressed. The entire family may find that they are making changes to accommodate the hearing impaired individual-speaking more loudly and clearly, avoiding settings with background noise, talking directly to the individual, etc.
When these lifestyle interventions fail, the solution may be a hearing device. However, many hearing impaired individuals resist this help because of the stigma wrongfully attached to hearing devices. With the technology available today and appropriate patient and family education, hearing devices can significantly enhance the quality of life for the hearing impaired and their families as well.
Hearing devices can improve the quality of life
Untreated hearing impaired people may have many problems that affect their lives. In 1999, the National Council on Aging carried out a survey among people over the age of 50 who were suffering from hearing loss. The survey revealed that in comparison to people using hearing devices, those who left their hearing loss untreated were more likely to report the following symptoms:
- Sadness and depression, worry, anxiety, and paranoia.
- Insecurity, and less social activity.
Those individuals who had their hearing loss treated reported:
- Better relationships with family and friends, higher self-esteem, and improved mental health.
- Greater independence and security.
- Improved sexual relations.
Researchers have also linked hearing loss to other major health issues such as high blood pressure, coronary artery disease, and elevated cholesterol and lipid profiles. One study correlated improved physical conditioning with better hearing, another suggested a relationship between overall cardiovascular health and hearing health. It seems apparent that individuals with significant untreated hearing loss seem to age less well, and that individuals without significant hearing loss or with treated hearing loss tend to be healthier and lead more vigorous lives.
What can hearing devices do for you?
If you think you may have hearing loss, remember that you are not alone. Over the past decade tremendous advances have been made in hearing instrument technology. We are now able to offer a superb level of sound quality in small instruments, some practically invisible to most observers.
Hearing devices will not restore normal hearing, however. The ear is just too complex to imitate. But, hearing devices can increase awareness of sounds and their sources. This is extremely important because communication cannot happen if you are not even aware that someone is attempting to communicate with you. With newer programmable and digital technology, hearing devices can make most speech available at comfortable levels, improve your understanding of conversations, and simply make communication easier.
Hearing devices will not eliminate background noise but often can be fine tuned and adjusted to optimize your hearing in your specific "hard-to-hear" environments. As with any assistive device, you must start with realistic expectations. Then, your hearing health professional should be able to assist you in selecting, fitting, setting, and adjusting your devices to best work for you. It takes commitment and a positive attitude to reap the benefits from hearing devices. Finally, hearing devices will provide no benefit if they are sitting in a drawer at home!
Developing reasonable expectations
Some people put on a hearing device and hear better right away. For most, there is more of an adjustment period. The single most important factor in the process is the attitude and commitment of the wearer. Just as if you had a joint replacement or other complicated medical procedure, you can expect to go through a period of adjustment as you become accustomed to your hearing devices. This will take some time. You'll need the willingness to go through that type of process, as well as the patience and determination to relearn a "new way of hearing."
Choosing hearing devices
There is no one particular hearing device that is best on the market today and is appropriate for every type of hearing loss. Selecting hearing devices depends upon your specific hearing loss, your social needs, your expectations, and most of all your personal preferences. You likely have heard horror stories about other people's experiences with amplification. Every hearing loss is different and everyone's listening needs are unique! Keep an open mind and maintain realistic expectations throughout the process of defining your hearing loss, deciding whether to treat it or not, selecting and adjusting to your hearing devices, and getting used to them.
Factors to consider:
- Personal hearing loss characteristics.
- Lifestyle: work, home, social, athletics, etc.
- Technology: analog, programmable, digital.
Three basic types of circuitry in hearing devices are:
- Conventional -- These devices increase the volume of all incoming sound with some minor adjustments possible. Have user-adjusted volume control. Add some noise and distortion to the sound signal through your device. Sometimes make loud sounds too loud and soft sounds not loud enough. Cannot change listening program based on your likes and dislikes. Analog signal. Generally the most economical type of device.
- Programmable - These devices are programmed in a hearing health professional's office with some flexibility in adjustment based upon your likes and dislikes or changes in your hearing over time. Some have multiple memory settings so you can adjust to different listening programs depending upon your environment. Tend to have a little distortion and noise with amplification, and soft sounds are treated differently from loud ones. They use analog signal and have automatic volume control.
- Digital - Today's most advanced devices. They are programmed in your hearing health professional's office utilizing special software packages. They allow for dramatic flexibility in adjustment based on your likes and dislikes or changes in hearing. Multiple channels allow for more precise personal amplification. Digital signal processing reduces feedback, and directional microphones can help manage background noise. Digital devices often have
multiple memory settings for personal adjustments as needed. Remote control devices available. The digital signal is clear and free from distortion. Soft sounds are treated differently than loud sounds. Tend to be the most expensive type of device.
Styles of hearing devices
After considering the various options available in hearing device circuitry, consider the style, size, and extra functions you want in a hearing device. The most popular types of hearing devices can be divided into four main categories:
Completely-in-the-Canal (CIC)
The smallest hearing devices, almost invisible in the ear. These are restricted to individuals with larger-than-average ear canals and mild to moderate hearing losses. They can be difficult to place and adjust. The small size demands a fair amount of dexterity on the part of the wearer.
In the Canal (ITC)
A bit larger than the CIC type, but still very cosmetically appealing to many device wearers. Also normally used in cases of mild to moderate hearing impairment.
In the Ear (ITE)
These devices are larger, tend to fill the "bowl" of the ear, usually have more features, and can accommodate larger sound amplifiers. Often easier to use than CIC or ITC models.
Behind the Ear (BTE)
The largest of the standard hearing devices. They offer the most flexibility in separating the electronics from the ear mold and flexibility in fitting. They are durable and allow the most power. Especially recommended for children.
Two ears vs. one ear
If you have hearing loss in both ears, two hearing devices are generally recommended. Dual fitting provides a more natural signal to the brain. This is how we were designed to hear! Enhanced hearing in each ear tends to help with understanding speech and locating the source of sound. Of course, this doubles the cost of obtaining hearing devices, which may be prohibitive to many individuals on fixed incomes. This issue should be carefully considered by you and your hearing health professional during the evaluation process.
Adjusting to life with hearing devices
There are physical adjustments to consider. At first, devices may feel funny in your ears. Your voice may sound strange to you when you first start wearing hearing instruments. This phenomenon is known as the occlusion effect. There are tiny microphones which are only a few inches from your mouth, so you will also hear yourself through your hearing devices. Most new devices are designed to minimize this. You may find their presence in your ears distracting. You may experience minor irritation of the external ear canals. This is usually easily correctable through minor hearing device adjustments by your hearing health professional.
Here's what many people report when they first wear hearing devices:
- It will take some time to adjust to wearing hearing devices.
- Your hearing in quiet environments should improve.
- Your hearing in situations with background noise should improve, but probably not as much as your hearing in quiet places.
- You likely will begin to notice sounds you haven't noticed or heard for some time, such as the hum of household appliances, or the chirping of a cricket.
Just like getting used to a pair of bifocals, you may experience some frustration at first, but it will pass in time. You'll need to make a conscious effort to wear your devices consistently, and work with them in different situations to understand their utility and limitations. The more you use your hearing devices, the sooner you'll adapt to better hearing.
Hearing Self-Check
- Do you frequently ask people to speak up or repeat themselves?
- Do you have difficulty in following a conversation in a crowded room?
- Do you have trouble communicating when the other person is a short distance from you?
- Do you have trouble hearing the telephone ring?
- Do you turn the TV volume up louder than what others need?
- Do you seem to hear better from one ear than the other?
- Do you find it helpful to sit up front at religious services, meetings, or gatherings?
- Do you seem to get tense and anxious at meetings or social gatherings?
- Do you have trouble following conversations between the front and back seats of a car?
- Do others comment on your inability to hear?