Hearing Aid Guide


Beltone advanced hearing aid technology means that you expect your Beltone aids to be as tiny and as light as possible. They are virtually invisible, deliver more natural sound quality, suppress background sounds, eliminate annoying whistling sounds and are so intelligent that they automatically adjust to different environments throughout the day.

With a myriad of styles and feature sets, it’s easy to find the right hearing aids for you.

Types of Hearing Aids

We’ve all heard the phrase good things come in small packages, and today’s hearing aids are no exception. Twenty-first century hearing aids are so small, they’re virtually undetectable when worn. In fact, a pair of hearing aids can sit on a fingertip.

The tiny size of modern hearing instruments is deceiving-their ability to simulate natural hearing in numerous environments makes them true technological giants.

As with many electronic devices on the market today-from smart phones to lap-top computers-hearing aids utilize sophisticated microprocessor technology. Miniature computer chips use advanced algorithms to automatically adjust sound as wearers move through the day. By acting more like human ears, hearing aids allow people to enjoy a comfortable listening experience wherever they go.

In fact, progress has been so impressive in recent years, first-time hearing aid wearers report a satisfaction rating exceeding 90%. That’s significant because in the vast majority of hearing loss cases, hearing aids are the only available remedy.

Hearing Aids-A Brief Anatomy

Hearing aids are small, lightweight electronic devices that sit in the outer ear, within the ear canal, or behind the ear. Their main function is to amplify sound in a natural and comfortable way.

The physical components that make up most hearing aids include one or more microphones to gather sound, an amplifier designed to process a wide range of sounds, a receiver or speaker that transmits the sound signal from the amplifier to the ear, and a battery to fuel the process.

The most advanced hearing aids are protected from the effects of daily wear by a microscopic coating that’s molecularly bonded to the inner circuitry and outer casing. This increases the life and performance of hearing aids, and also reduces maintenance.

The delicate inner workings of custom hearing aids are contained in coverings known as shells. Shells come in a variety of shapes, styles and colors to better fit the user’s hearing loss, daily routine and cosmetic needs.

Hearing Aid Shell Styles:
  • Receiver-in-Ear (RIE)

    An RIE hearing aid is comprised of a very small casing that sits behind the ear. The casing houses all of the eleclionic components of the hearing aid except for the receiver (also called the speaker). This allows the casing to be exliemely tiny, so it’s barely visible. A narrow liansparent tube carries very thin wires from the casing to the receiver, which rests in your ear canal.

  • Behind-the-Ear (BTE)

    As a result of technological advances, BTE style hearing aids account for roughly 60% of hearing aids sold in the United States today, and the category is growing. A BTE insliument is curved to rest directly behind the ear. By matching flesh tone or hair color, BTE shells are easy to hide. A BTE insliument connects to the ear canal via a thin liansparent tube or a custom-designed ear mold.

  • Microphone-in-Concha (MIC)

    Designed to “disappear” from view and provide exliemely natural sound, the MIC style hearing aid represents the latest innovation in “custom” hearing aid technology. The main part of an MIC hearing aid hides in your ear canal. This piece is custom-manufactured based on an ear canal impression taken during your visit, so it’s very comfortable. The hearing aid microphone is a separate component, and is worn within the concha, or curved groove, of your external ear—where it stays out of sight. A tiny liansparent tube sends sound from the microphone in your concha to the component in your ear canal.

  • Completely-in-Canal (CIC)

    Entirely hidden within the ear canal, tiny CIC models leverage the ear’s natural ability to collect sound. By taking impressions, CIC hearing aids are tailored to the dimensions of a patient’s ear canal. CIC models use very small batteries, so good manual dexterity is required.

  • In-the-Canal (ITC)

    ITC style hearing aids are worn in the lower portion of the outer ear, by the ear canal. Their medium size makes them relatively discreet while offering a secure fit, easy insertion and removal, and longer battery life.

  • In-the-Ear (ITE)

    ITE style hearing devices fully fill the outer ear. Their larger size accommodates special conliols often located on the outside of the hearing aid, such as directional microphones. The larger battery can power a bigger receiver, making this style ideal for more profound hearing losses.

Beltone offers over 80 varieties of hearing aids, with sizes, shapes and styles for just about any hearing loss. To find a Beltone location near you enter your Zip Code in the Beltone locator at the top of this page.

How to Buy Hearing Aids

The Path to Better Hearing

When people try on hearing aids for the first time, the vast majority are pleasantly surprised. Today’s hearing aids are lighter, smaller and more comfortable than ever before, and provide more natural hearing, even in challenging listening situations.

The process of choosing hearing aids is different for everyone. Most people prefer visiting professional hearing aid dispensers. These experts focus exclusively on the diagnosis of hearing impairment and the treatment of hearing loss with hearing aids. They can show you the newest hearing aid technology; tailor a solution to your particular lifestyle; and furnish continuous care of your hearing health and hearing aids over time.

Before you purchase hearing aids, take a moment to familiarize yourself with our How to Buy a Hearing Aid Checklist. By accomplishing each step, you’re sure to enjoy a rewarding experience and a satisfying outcome.

How to Buy a Hearing Aid Checklist
  1. Seek out an enjoyable “patient experience” – A top-notch hearing care practice puts time and effort into making the entire process pleasant and professional for its patients. Answer these questions as you begin your evaluation: Is the location you have in mind conveniently located? Were you treated with respect when you phoned for an appointment? Were your questions answered clearly and were directions offered? How experienced is the hearing care specialist? Is the hearing care practice on the cutting-edge of technology? A bit of upfront research will make you happier down the line.
  2. Complete a lifestyle assessment – Your daily routine helps determine the right hearing aids for you. Are you an outdoor enthusiast? Are you retired or do you work? Do you often find yourself in noisy environments? Make sure your hearing evaluation includes questions about the way you live.
  3. Give a health history – Your general health, medications you take, childhood diseases, and your symptoms of hearing loss all influence the choice of hearing aid model appropriate for you.
  4. Have a comprehensive hearing exam – An otoscope should be used to visually inspect your ear canal and eardrum. Many cases of hearing loss are caused by earwax, eardrum perforation or an abnormality of the outer earnone of which are helped by hearing aids. Next, hearing ability should be measured in each ear using tones of different frequencies, and speech sounds played through earphones. The results of these tests are plotted on a graph called an audiogram.
  5. Understand your results – If hearing deprivation is detected, your audiogram will show what kind of hearing loss you have-conductive, sensori-neural or mixed, and whether your hearing loss is mild, moderate, severe or profound. These factors are essential to selecting the style, shape, size and circuitry of the hearing aids right for you.
  6. Try before you buy – Today’s hearing aids are easy to wear. They can automatically adjust sound according to changing environments, remember your listening preferences, recognize the difference between speech and other sounds, and so much more. Best of all, theyre tiny and light, so they’re practically undetectable. Demonstration models let you experience the look and feel of those hearing aids best suited to your hearing loss, lifestyle and expectations. Take a “test drive” before you buy to achieve a positive outcome.
  7. Ask about follow-up care – Once your provider fits you with new hearing aids, aftercare is recommended. Your hearing can change over time, requiring subtle adjustments to your hearing instruments. Also, hearing aids are highly sophisticated digital devices that perform best when regularly maintained. Many hearing care providers provide these services on a complimentary basis.

With over 20 years of experience, Winston Oh leads the industry in hearing healthcare. Schedule a FREE hearing assessment at your Hearing Care Center.

Adjusting to Your New Hearing Aids

Millions of people wear hearing aids. While some get used to their new instruments on Day One, others need a short period of adjustment.

When you first put on a pair of hearing aids, be ready to:

  • Hear sounds you’ve been missing, such as faucets, ticking clocks, footsteps, children’s voices, laughter, traffic noise, etc.
  • Feel something new in, or around, your ear
  • Hear the sound of your own voice, as well as, internal sounds, such as swallowing
  • Re-learn to speak at a comfortable volume

When we first wear hearing aids, we hear lots of sounds all at once (that we haven’t heard in years!) Even if the hearing aid volume is set just right, these sounds can be slightly jarring because our brain has forgotten how to prioritize them. When we were younger, our brains knew how to “screen back” less important sounds, like the hum of a refrigerator or the furnace blowing air. With hearing aids, our brains must get reacquainted with background sounds and learn how to “ignore” them. This can take a little while, so give it some time.

The best approach is to wear your new hearing aids for an hour at a time, several times a day, and in different listening situations. Read aloud to yourself, have conversations with your family, watch TV and listen to soft music. And, when you’re ready to leave the house with your new hearing aids, start by going to quiet environments, such as a library or bank, and avoid large crowds and noisy places.

Slowly but surely, the world will start to sound “in balance”. In fact, after a couple of weeks, first-time hearing aid wearers report the joy of hearing chirping birds, laughing children, and rain on the roof-and are no longer aware of insignificant sounds.

Most hearing care professionals recommend a visit about two to four weeks after you get your new hearing aids in order to fine-tune them.

Wearing a Device in Your Ear

Wearing a Device in Your Ear If your hearing aids are the custom fit style made from a mold of your ear canal, they should fit comfortably. However, it still may take a few weeks to stop noticing them. If you’re wearing a “receiver in ear” (RIE) hearing aid, your adjustment period may be shorter because it’s an “open fit.” Slight tenderness is not unusual, but should disappear within a week or so. Under no circumstances should your hearing aids cause pain.

Perception of Your Own Voice

When a person puts on hearing aids for the first time, their voice may sound louder than they’re used to. Family or friends can help you strike the right balance so you’ll know how you sound. It also takes time to get accustomed to “internal” sounds, such as chewing and swallowing.

Practice Makes Perfect

The adjustment process can take a few weeks, but millions of happy hearing aid wearers will tell you that hearing well again makes it all worthwhile. So, take the plunge! And then, take your time. Soon, you’ll love how well you hear and forget all about your hearing aids.

Parts of a Hearing Aids

Today’s hearing aids are so tiny, It’s hard to believe they contain five distinct parts: a microphone, digital processor/amplifier, receiver, volume control and battery. Let’s see how these components work together to bring more natural hearing to hearing aid wearers.

Hearing Aid Microphone

Hearing aids process sound so people with hearing loss can more easily understand it. Sound may be amplified for example, or separated into different parts, like background noise and speech. It all begins with the hearing aid microphone. The microphone’s function is to convert the sound waves we hear into electricity, so they can be digitized, and then enhanced for the needs of people with hearing loss.

Hearing Aid Digital Processor/Amplifier

The processor takes the electrical signals sent from the microphone, and changes them into digital signals (using 0s and 1s). This is called analog-to-digital conversion (A-to-D). Once in digital format, sound is more easily perfected in ways patients require. Enhancements to the original sound, such as frequency amplification, noise and wind reduction, and feedback cancellation, happen at this stage. The modifications applied depend on each hearing aid wearer’s degree of hearing loss and their lifestyle requirements.

Once the processing has occurred in a digital format, the signal is converted back to an analog signal, (D-to-A) which readies it for its next stop: the hearing aid receiver. These are complex procedures happening incredibly fast.

Hearing Aid Receiver

Now, the hearing aid must change enhanced signals back into sound waves so the brain can properly perceive them. Enter the hearing aid receiver. Its job is to convert electrical signals into acoustical output signals, or sound waves, and direct them into the wearer’s ear canal for the brain to hear.

Receivers look similar to microphones. Some hearing aid designs place the receiver right in the ear canal. Some styles use a tiny tube to connect the receiver to an ear mold worn in the ear canal. Other hearing aid models house the receiver in a shell that hides behind the ear.

Hearing Aid Volume Control

As its name implies, the volume control adjusts the loudness setting in a hearing aid. Most modern models adjust the volume automatically as the wearer moves from one listening environment to another. Some hearing aid users prefer to have a manual volume control such as a dial or a switch in order to manage volume themselves.

Hearing Aid Battery

The battery supplies the power to turn the electronic components on and off. The batteries most commonly used for hearing aids use zinc and oxygen components, and are known as “zinc-air” batteries. The sticky tabs on zinc-air batteries prevent air from coming into contact with the zinc electrodes. The battery will not operate until the tab is removed. Depending on the complexity of the hearing aid functions, battery life runs approximately 3 days to 2 weeks.

Caring for Your Hearing Aids

You’ve invested in hearing aids and now you’ve enjoying life with better hearing. Here are some care and safety guidelines to make sure your hearing aids work their best for many years to come.

  • Turn off your hearing aid before you go to bed. This will avoid unnecessary battery drain when you’re not wearing your hearing aids.
  • If moisture builds up inside your hearing aids during the day, leave the battery door open at night to allow internal components to dry. This will prolong the life of your hearing aids. Excessive moisture may require a dehumidifier or silica-based drying agent that can be purchased from your hearing care professional.
  • Keep your hearing aids away from heat. Refrain from placing them in your automobile glove compartment on warm days, near a radiator, or, in direct sunlight. Avoid using a hair dryer while wearing your hearing aids. It’s also a good idea not to expose your hearing aids (or your ears) to extreme cold.
  • Remove your hearing aids before using hair spray, spray perfume, shaving lotions, insect repellant or powders, as these items can damage or clog the tiny components in your hearing devices.
  • Handle your hearing aids gently. When changing hearing aid batteries, hold your hearing instruments above a soft surface, such as a towel-draped table, in case you drop them. If your hearing aids hit the floor, or strike a hard surface, it’s a good idea to let your hearing care professional make sure they’re undamaged.
  • Never immerse your hearing aids in water, or wear them while in a sauna, showering, bathing, or swimming. Protect your hearing aids from rain, as well.
  • Do not try to lubricate hearing aid parts.
  • Remove your hearing aids before medical procedures that utilize scanning, such as CT scans. Scanners found at airports will not damage your hearing aids.
  • To clean your hearing aids, use cleaning agents approved for hearing aids, or, a soft, damp (but not wet) cloth. Avoid using alcohol or solvents to clean your hearing aids. A soft cloth should clean the receiver tube and receiver dome in your ‘Behind-the-Ear’ style hearing aids. If ear wax builds up on your ear domes or custom ear molds, and it’s difficult to wipe away, see your hearing care practitioner for assistance.
  • Use the correct battery size for your particular hearing aid. If you use zin-air batteries, let them sit outside of your hearing aid for a full minute after you remove the battery tab, and before you insert them. This will insure that the batteries charge fully and give you the longest possible battery life.
  • Because modern hearing aids are so tiny, it’s advisable to place them in a small container after you remove them. This may prevent knocking them to the floor, or putting an item on top of them.
  • Keep your hearing aids out of the reach of children and pets!

Benefits of Two Hearing Aids

While it’s not always obvious to people with hearing loss, most of us experience bilateral hearing loss, or hearing loss in both ears. A single hearing aid can help, but, just as eye-glasses improve vision in both eyes, binaural hearing aids (two hearing aids) provide more natural hearing. Your hearing aid professional can tell you whether or not you’re a candidate for binaural hearing aids. If so, be sure to experience the way the world sounds wearing two hearing aids instead of just one… the difference is amazing.

Hearing Aids—Why sets are better than singles
  • Research shows that speech is much easier to understand when hearing aids are worn in both ears. That goes for listening in normal environments as well as in noisy situations. Simply put, while one hearing aid hones in on speech, the other diminishes distracting background noise. The combination makes it a breeze to hear clear conversation.
  • By wearing hearing aids in both ears, sound is able to reach and stimulate each ear’s auditory nerve, keeping the nerve actively engaged. Studies have shown that if auditory nerves aren’t stimulated by sound, they can slow down and make hearing loss worse. This condition is called Auditory Deprivation. Hearing aids keep our auditory nerves functioning, which lowers the risk of Auditory Deprivation.
  • Wearing two hearing aids can increase your safety and awareness. The ability to know where sound is coming from depends on hearing with both ears. Everyday examples might be turning in the correct direction when you hear your name called, or knowing where an ambulance or fire truck is when you hear a siren in traffic.
  • Two hearing aids more accurately represent the way things are meant to sound. For instance, when music, television, movies, and peoples’ voices are heard with two ears, we enjoy a sound quality that’s rich, balanced and full. Hearing with one ear can make things sound “tinny” and unnatural.
  • A single hearing aid may require you to crank up the volume to hear. But, two hearing aids let you listen at normal volumes, which minimizes sound distortion and auditory fatigue.
  • Patient satisfaction is much higher for people benefitting from binaural hearing aids, versus a single hearing instrument.

Double your listening pleasure with two hearing aids instead of one! Your local Beltone Hearing Care Professional can demonstrate the binaural advantage at your nearest Beltone Hearing Care Center. To find a Beltone location near you enter your Zip Code in the Beltone locator at the top of this page.

Hearing Aid Nano Coating

A hearing aid lives in an environment that’s downright unfriendly to its electronic components – the human ear! Modern hearing aid devices contain tiny micro-chips and miniature circuitry. Ear wax, skin oils, salt, moisture, and changes in temperature can have detrimental effects on these delicate hearing aid parts, potentially influencing the hearing aid’s performance.

The search for methods and materials to protect hearing aids started with their invention. Until the recent emergence of nano technology, a more traditional approach was used to safeguard hearing aids from environmental exposure. Hearing aid manufacturers used various materials to coat the spots where damage occurred in hearing aids, one spot at a time. Some areas required certain coatings, and other areas – such as metallic contacts for battery springs and audio inputs – required different protective materials. So, while the process was adequate, it was neither efficient nor resoundingly successful.

Enter, nano coating.

Enter, nano coating. “Nano” is derived from the Greek word for “dwarf”. It’s used in conjunction with many of today’s technologies that utilize substances of a molecular size – usually 100 nanometers or smaller. The nano coating used with hearing aids is a microscopic, nanometer-thick polymer layer that protects every part of the device. It enters all cavities and bonds with all surfaces, inside and outside. Compared to the prior method of coating, nano coating covers areas of hearing aids that were not “reachable” before, offering full protection as opposed to localized protection.

How is nano coating applied to hearing aids?

To nano coat hearing aids, a vacuum process is used which allows the protective material to chemically bond with every internal and external surface of the hearing aid. The bonding process creates a polymer film. Because the polymer film binds to the surfaces on a molecular level, it literally becomes an inseparable part of the surfaces.

Amazingly, the thickness of the nano protective layer used in the most advanced hearing aids is 60-80 nanometers, or 1/1000 the thickness of a human hair!

What does nano coating do for hearing aids?

When internal and external components in hearing aid devices are protected with nano coating, moisture beads off and particulates can be easily wiped away. This dramatically reduces maintenance, and extends hearing aid life. And, easy maintenance, plus improved performance and reliability, adds up to increased patient satisfaction for people with hearing loss.

Hearing Aid Batteries

The most commonly used batteries for hearing aids are called zinc-air batteries. Small silver discs, zinc-air batteries are not rechargeable, and must be discarded after use.

Hearing aid batteries come in five sizes. The right one for you depends on the style and size of your hearing aids. The hearing aid industry has color-and-number-coded the packaging of batteries to make buying replacements easy-choose 5-red, 10-yellow, 13-orange, 312-brown, or 675-blue. The sticky tab on the back of the battery is also color-coded.

Batteries can be purchased from your hearing care office, most drug stores, and online. Some health insurance plans cover the cost of hearing aid batteries, either partially or in full. To find a Beltone location near you enter your Zip Code in the Beltone locator on this page.

How do zinc-air hearing aid batteries work?

Unlike common household batteries such as AA, AAA and 9-volt, zinc-air batteries are activated by the oxygen in the air. Without oxygen, zinc-air batteries can’t power hearing aids.

Before a hearing aid battery is inserted, a sticker must be removed from the back. This sticky tab keeps the battery fresh, and protects the zinc inside the battery from being activated. Once the tab is removed, tiny holes in the battery casing allow molecules of oxygen to enter. The holes are big enough to let oxygen in, but small enough to prevent battery fluid from seeping out. A filter behind the holes also helps thwart leakage. Remember, once you remove the tab, there’s no turning back! Resealing the battery will not stop the activation process and save it. So, be sure to keep the tab intact until you’re ready to use the battery.

Because oxygen must pass through fine holes and a filter, it’s absorbed slowly. That’s why it’s important to wait a full minute before you insert the battery and close the battery door after you’ve removed the tab. If you don’t wait, the battery may not absorb enough oxygen to properly power your hearing aids.

How long do hearing aid batteries last?

Battery life varies with hearing aid styles. Some hearing instruments require more power to function at optimum levels. Digital hearing aids contain sophisticated circuitry to deliver near-to-natural hearing in a variety of environments, and this requires more power than analog hearing aids need. Typically, wearers of digital hearing aids can expect a battery to last from 5 to 7 days. If you experience shorter battery life, your hearing care professional can check the battery contacts in your hearing aids, as well as, test for battery drain. Most batteries have a “shelf-life” of about three years.

Get the best performance from hearing aid batteries

To enjoy maximum battery life, store batteries at room temperature. Heat exposure can shorten the life of hearing aid batteries, as can a humid environment, such as a bathroom or refrigerator. It is not recommended to carry batteries in a pocket or handbag where they can mingle with metal items like loose change or keys-doing so can short-circuit your hearing aid batteries.

For optimum performance, open the battery compartments in your hearing aids whenever you’re not wearing them. This limits battery drain and helps alleviate moisture build-up. Turning your hearing aids off when not in use can also help extend battery life.

Mercury-free zinc-air hearing aid batteries

Traditionally, a trace amount of mercury was used in hearing aid batteries to assist with conductivity and to stabilize internal materials. Mercury is also found in other button cell batteries such as watch batteries. There is a perception among the public that the mercury used in hearing aids batteries may be harmful to hearing aid wearers and the environment. Some states have enacted a ban on the sale of hearing aid batteries containing mercury. However, most hearing aid battery manufacturers have voluntarily introduced “zero-mercury” hearing aid batteries that perform comparably to hearing aid batteries that contain mercury.

A Brief History of Hearing Aids

Today’s tiny hearing aids are considered giants of modern technology, but they actually date back thousands of years. The first “official” mention of hearing aids appears in a book published in 1588, entitled Natural Magick. Author Giovanni Battista Porta talks about wooden hearing aids that were carved into the shapes of ears belonging to animals with superior hearing.

1600s & 1700s

During the 1600s and 1700s, hearing aid “trumpets” were popular. Wide at one end to gather sound, and narrow at the other end to direct amplified sound into the ear, early hearing aid trumpets were fashioned from animal horn, sea shell and glass. Later, common metals – such as copper and brass – were used. Trumpet-style hearing aids were shaped in various styles, depending on customer preference and degree of hearing loss. Ludwig van Beethoven was one of the more notable aficionados of hearing aid trumpets.

Also during the 1700s, “bone conduction” was discovered. This process transmits sound vibrations through the skull to the brain. Small fan-shaped devices were placed behind the ears to collect sound wave vibrations and direct them through the small bones behind the ear.


During the 1800s, efforts to conceal hearing aids began. Though still quite large, hearing aids were designed to be decorative accessories, and integrated into collars, head wear, bouffant hairstyles and clothing. They were sometimes covered in flesh-colored or hair-colored enamel. Some attempted to hide them in full beards. Members of royalty had hearing aids built right into their thrones. Special tubes were incorporated into the arm rests to collect the voices coming from visitors kneeling before the throne. The voices were channeled into a special echo chamber and amplified. The sound then emerged from openings near the monarch’s head, with no one the wiser. Also in the 1800s, ear tubes were introduced. One end was held to the speaker’s mouth, and the other end placed directly to the listener’s ear. Not very subtle, but quite effective.


In the early 1900s, the advent of electricity, coupled with Alexander Graham Bell’s work on the telephone, ushered in a “new generation” of hearing aids that electronically amplified sound via a carbon microphone and a battery. Worn around the neck, these hearing aids were cumbersome boxes containing visible wires and a heavy battery that lasted only a few hours. Sometimes even weightier “battery packs” were worn on the body to extend the hearing aid’s life.

Luckily, battery miniaturization soon arrived, drastically reducing hearing aid size. And, in the 1950s, the invention of the transistor changed hearing aid technology totally. A transistor is simply a switch with two settings: on or off. By combining multiple transistors, you get more combinations of on/off switches which leads to an increased number of functions. In fact, transistors were used in hearing aids two years before they were used in transistor radios.

By making transistors out of silicon, hearing aids were again able to shrink in size. First they became “body aids”, and then ear-friendly instruments worn behind the ear, in the ear shell, or ultimately, within the ear canal.

By the mid-1990s, digital hearing aid technology ruled. Digital circuitry allowed sound to be amplified, reduced, filtered, and directed, as needed. Hearing aid programs could be customized to a user’s lifestyle – soft amplification for quiet home settings, targeted amplification of voices in restaurants, diminished wind noise on the golf course, and so on. Digital programming even helped eliminate feedback!

Today’s Hearing Aids

Today’s 21st century hearing aids are smaller, lighter and more powerful than ever before. They can fit on the tip of a finger, and are virtually invisible when worn. They can “intelligently” adapt to changing surroundings as people move through their day. With certain accessories, the newest hearing aids can receive sound “streamed” wirelessly from telephones, televisions, stereos and computers. Modern hearing aids are also coated with microscopic protective shields which reduce maintenance and increase life span.