Hearing Aids

What Are Hearing Aids and How Do They Work?

Hearing aids are electronic devices designed to amplify sound for individuals with hearing loss. While they cannot restore normal hearing, they significantly improve auditory perception in various environments. Here’s how they work:

1. Sound Reception: The microphone captures sound waves from the environment.

2. Digital Processing: For digital hearing aids, a computer chip processes the sound waves into electrical signals, adjusting them based on your hearing loss profile. The chip is also responsible for cancelling out noises and fine tuning speech. The quality of the chip can really make a difference in the quality of the sound. That's where high end hearing aids get to shine the most!

3. Amplification: The amplifier boosts the processed signals to make them audible.

4. Sound Delivery: The speaker delivers the amplified sound into the ear canal.

Modern hearing aids also feature advanced technologies such as noise reduction, directional microphones, and Bluetooth connectivity for seamless integration with smartphones and other devices.

Types of Hearing Aids

Hearing aids come in various styles, each suited to specific needs and preferences. Hearing aids are divided into 2 large categories, which then have different models: 

1. In-the-ear (ITE): 

   These are custom-made devices that contain all the components of the hearing device in a unit that fits inside the ear. These are usually better for people that do not have an important hearing loss because they cannot amplify sounds very much (limited power). They are also not best for people with small or abnormal ear canals, those who produce a lot of wax,  and those who have trouble with dexterity (since they are small and can be hard to handle). Another downside is their smaller battery.

2. Behind-the-ear (BTE):
   These devices sit behind the ear and connect to a custom earmold via a tube. They are ideal for more advanced hearing hearing loss due to their higher power, durability, and ease of handling. BTE models often include features like long battery life and wireless connectivity. The biggest downside is that they are larger and usually more visible.

This chart from Johns Hopkins medicine clearly shows the differences between the two categories:

1. In-the-Ear (ITE)

A) Invisible-in-the-Canal (IIC)

The smallest option available, fit fully inside the ear canal, making them very discreet (actually almost invisible!). They are best for mild to moderate hearing loss but may lack advanced features due to their compact size. They are inserted by a health care professional (ENT or audiologist typically). They do not need a battery change, and never need to be removed for sleeping, showering or exercising, but need to be replaced every few months.

B) In-the-canal (ITC) and Completely-in-the-canal (CIC) 

These smaller devices fit partially or fully inside the ear canal, making them discreet. They are best for mild to moderate hearing loss but just like the IIC devices they will lack advanced features due to their compact size.

C) "Low profile" In-the-ear (ITE)

Classic in-the-ear device. They are custom-fitted to fill either the full outer ear (full-shell) or part of it (half-shell). They are easier to handle, and suitable for mild to severe hearing loss.

2. Behind-the-Ear (BTE)

A) Receiver-in-the-Ear (RITE)

Also known as Receiver-in-Canal (RIC), these combine a behind-the-ear component (the processor) with a receiver (speaker) placed in the ear canal. These are very discreet, and the outer ear usually has no hardware visible. They are the smallest BTE devices. They offer natural sound quality and are suitable for mild to severe hearing loss.

B) With earmold (classic behind-the-ear, BTE)

As mentioned above, these devices sit behind the ear and connect to a custom earmold via a tube. The earmold occupies the outer ear, and is visible. They are ideal for moderate to profound hearing loss due to the added power provided by the earmold, durability, and ease of handling. BTE models often include features like long battery life and wireless connectivity.

This picture illustrates what the models look like in real life:

What are we referring to when talk about CROS/BiCROS Systems?

CROS (Contralateral Routing of Signals) and BiCROS (Bilateral Contralateral Routing of Signals) hearing aids are designed for individuals who are completely deaf in one ear (single-sided deafness) or with one ear being much weaker than the other (asymmetrical hearing loss). These devices help users hear sounds that get to their deaf side by transmitting those sounds to their better-hearing ear. It's important to note that CROS and BiCROS do NOT restore hearing in the deaf ear. It does NOT restore stereophonic hearing (hearing from both ears). Instead, they improve spatial awareness and communication because patients can hear the sounds coming both sides of their heads (although all the sounds are heard only in the good ear). 

When Are CROS Hearing Aids Recommended?

• For single-sided deafness with Normal Hearing in One Ear: CROS devices consist of a transmitter on the deaf ear that picks up sound and sends it wirelessly to a receiver on the better ear.

• Key Benefit: Eliminates the "head-shadow effect," where sounds from the deaf side are blocked, allowing users to hear from all directions.

When Are BiCROS Hearing Aids Recommended?

• For single-sided deafness with Hearing Loss in the Better Ear: BiCROS systems amplify sounds for the better ear while also transmitting sounds from the deaf ear.

• Key Benefit: Combines amplification and sound routing to improve clarity for individuals with asymmetrical hearing loss.

Benefits

1. Improved Awareness: Hear sounds from both sides, reducing missed conversations or alerts.
2. Better Communication: No need to reposition yourself to use your "good" ear.
3. Non-Invasive Solution: No surgery is required, making it a practical option.

Limitations

• No Binaural Hearing Restoration: Users may still struggle with localizing sound direction.
• Challenges in Noise: Background noise from the deaf side may interfere with clarity.

Can Any Type of Hearing Loss be Fitted with Hearing Aids?

No, not all types of hearing loss can be effectively treated with hearing aids, as their suitability depends on the nature and severity of the hearing impairment. You can read more about the different types of hearing loss here. Here’s an overview of how hearing aids align with different types of hearing loss:

1. Sensorineural Hearing Loss:
   This is the most common type of hearing loss, caused by damage to the inner ear or auditory nerve. Hearing aids are highly effective for this type because they amplify sounds to compensate for the reduced ability of the inner ear to process sound. The most relevant parameter that needs to be considered when fitting hearing aids for sensorineural hearing loss is something we call Word Recognition (or Speech discrimination). Speech discrimination refers to the ability to understand and differentiate speech sounds, which directly affects the success of hearing aid use. This is the clarity of the sound. If speech discrimination is poor (less than 50%), even amplified sounds may remain unclear, limiting the effectiveness of hearing aids. In this article, I explain how speech discrimination is analogous to the channel on a radio. If you are on the wrong channel, increasing the volume will only increase the white noise. However, rapid application of hearing aids can preserve speech discrimination abilities by stimulating hearing pathways in the brain and improving clarity over time. Individuals with better speech discrimination scores (e.g., 80% or higher) tend to achieve more satisfying results with hearing aids, while those with lower scores may require additional strategies like frequency-shifting features or auditory training for optimal benefit.

2. Conductive Hearing Loss:
   This occurs when sound cannot pass through the outer or middle ear due to blockages, infections, or structural issues. While hearing aids can help amplify sound for conductive hearing loss, medical or surgical interventions (e.g., bone-anchored hearing aids or middle ear implants) are often required for optimal results.

3. Mixed Hearing Loss:
   A combination of sensorineural and conductive hearing loss, mixed cases may benefit from hearing aids alongside medical treatments. The choice of device depends on the severity and balance between the two components.

4. Profound or Total Deafness:
   Hearing aids are generally ineffective for individuals with profound deafness in both ears since amplification cannot restore lost auditory function. Cochlear implants or other assistive technologies may be more appropriate.

How Hearing Aids Help With Tinnitus

Many modern hearing aids include tinnitus masking features that emit soothing sounds like white noise or nature sounds directly into the ear canal. These features help reduce the perception of tinnitus by shifting focus away from ringing sensations and improving overall auditory comfort.

Steps to Obtain a Hearing Aid

Obtaining a hearing aid involves several steps:

1. Hearing Test: Visit an audiologist for a comprehensive evaluation of your auditory sensitivity across different frequencies and speech comprehension abilities.

2. Medical Clearance: In some cases, an ENT specialist may need to ensure there are no underlying conditions causing your hearing loss.

3. Device Selection: Choose a device based on your audiologist’s recommendations, lifestyle needs, and budget.

4. Fitting Appointment: The audiologist programs your device according to your audiogram results.

5. Trial Period: Many clinics offer trial periods during which you can test your device in real-world scenarios before committing.

Where to Get Hearing Aids

1. In Canada

In Canada, you can purchase hearing aids from:

• Audiology clinics 
• Retailers specializing in hearing care products
• ENT specialists who work alongside audiologists.

2. In Quebec

Quebec residents can only obtain hearing aids through an audioprosthesist (hearing aid specialist). They often work alongside ENT specialists and audiologists in specialized clinics. Some also have an independent practice.

Prescription hearing aids Vs Over-the-counter (OTC) Hearing Aids

• Over-the-counter (OTC) hearing aids are devices designed for adults with mild to moderate hearing loss. They can be purchased directly from stores or online without a prescription, hearing test, or professional fitting. OTC hearing aids are self-programmed by the user, often using apps or manual controls, and are more affordable than prescription hearing aids.
  
  
• Prescription hearing aids are tailored to all levels of hearing loss, including severe cases, and require an evaluation and fitting by a licensed audiologist or hearing specialist. These professional devices offer advanced features like precise customization, greater amplification, and ongoing support for adjustments. While OTC hearing aids are convenient and cost-effective for simpler needs, prescription aids provide a higher level of care and functionality for complex or profound hearing loss.

In Canada

Hearing aids must be prescribed by an audiologist or ENT specialist as they are classified as medical devices under strict regulations. OTC devices are not yet available in Canada due to regulatory differences.

In the U.S.

OTC hearing aids became available in 2022 for mild-to-moderate hearing loss without requiring prescriptions. These devices are less customizable than professional-grade options but offer affordability and convenience.

Average Cost of Hearing Aids

In Canada

The cost of a pair of hearing aids typically ranges between $4,000 and $8,000 depending on technology level, features like Bluetooth connectivity or tinnitus masking, and brand reputation.

In Quebec

Costs are similar but may be reduced by provincial subsidies from organizations like RAMQ (Regie de l’assurance maladie du Quebec), CNESST, SAAQ, or Veterans Affairs Canada.

What to Expect after Purchasing Hearing Aids

Adjusting Your Hearing Aids

Once you’ve purchased hearing aids, they need to be properly programmed and adjusted to match your specific hearing needs. This process ensures that you get the best possible sound quality and comfort from your devices.

1. Initial Programming

• Your audiologist will program the hearing aids using specialized software based on your hearing test (audiogram).

• The settings will be customized to amplify specific frequencies where you have hearing loss while keeping sounds comfortable.

• Some models use real-ear measurements, where a small microphone is placed in your ear canal to fine-tune the amplification in real time.

2. Getting Used to the Sound

• At first, voices and environmental sounds may seem different or even overwhelming as your brain adjusts to hearing frequencies it had been missing.

• It takes time to adapt—typically a few weeks—so patience is key.

• Start by wearing your hearing aids in quiet environments and gradually introduce them into noisier settings.

3. Follow-Up Appointments

• Expect to have multiple follow-up visits with your audiologist for fine-tuning.

• Adjustments may be needed to improve clarity, reduce background noise, or enhance comfort.

• If you experience feedback (whistling sounds), distortion, or discomfort, these can be corrected through reprogramming.

4. Customizing for Different Environments

• Many modern hearing aids have different programs for quiet conversations, noisy places, music listening, and phone calls.

• Some models automatically adjust based on the environment, while others allow you to switch settings manually using a button or smartphone app.

• If you struggle in specific situations, your audiologist can tweak the programming to optimize performance.

5. Ongoing Adjustments

• Your hearing needs may change over time, requiring further programming updates.

• Hearing aid technology evolves, and software updates may improve performance.

• Regular hearing checkups ensure that your devices remain effective and comfortable.

By staying engaged in the adjustment process and working closely with your audiologist, you can maximize the benefits of your hearing aids and enjoy better hearing in all aspects of life.

Follow-Up Care 

After investing in hearing aids, proper care and maintenance are essential to ensure their longevity and optimal performance. Here’s what you need to know:

1. Daily Cleaning

Hearing aids are exposed to earwax, moisture, and dust, which can affect their function. To keep them in good condition:

• Wipe them down daily with a dry, soft cloth.
• Use a brush or wax pick (provided by your audiologist) to clean the microphone and sound ports.
• Avoid using water or cleaning solutions, as they can damage the electronics.

2. Battery Care & Charging

• For battery-powered models, replace batteries as needed, usually every few days to weeks depending on usage.
• For rechargeable models, charge them overnight in the provided charging case. Ensure the charging ports are free from dust and debris.

3. Moisture Protection

• Keep hearing aids dry by storing them in a protective case when not in use.
• Consider using a dehumidifier or drying kit, especially in humid climates or if you sweat frequently.
• Never wear hearing aids in the shower, while swimming, or in heavy rain.

4. Regular Checkups & Adjustments

• Expect follow-up visits with your audiologist for adjustments as your ears adapt to the devices.
• Periodic professional cleanings help remove deep wax buildup and ensure proper function.
• If you notice changes in sound quality, discomfort, or feedback (whistling), schedule an appointment for evaluation.

5. Handling & Storage

• Always handle hearing aids with clean, dry hands.
• When not in use, store them in a safe, dry place away from pets and small children.
• Avoid exposing them to extreme temperatures, such as direct sunlight or freezing conditions.

By following these simple care and maintenance steps, you can extend the lifespan of your hearing aids and ensure they continue to provide the best possible hearing experience.

Lifespan of Hearing Aids

Hearing aids generally last 3–7 years depending on usage and maintenance. Regular servicing can extend their lifespan while ensuring consistent performance over time.

Investing in hearing aids is an investment in better communication and quality of life. By understanding their types, costs, maintenance needs, and benefits, you can make informed decisions that lead to improved well-being!