Hearing Aids & Listening Services

Hearing Aids & Listening Services for DHH

Hearing Aid is the primary assistive device for any person who is deaf or is hard of hearing. This page covers the basic principle of working for the aids and their types, information about selecting / buying hearing aids in India, major hearing aids brands and wireless listening devices.

A hearing aid is a device designed to improve hearing by making sound audible to a person with hearing loss. Hearing aids are classified as medical devices in most countries, and regulated by the respective regulations. Small audio amplifiers such as PSAPs or other plain sound reinforcing systems cannot be sold as "hearing aids".


Most hearing aids, typically digital, work by amplifying sound through a three-part system:

  • The microphone receives sound and converts it into a digital signal.

  • The amplifier increases the strength of the digital signal.

  • The speaker produces the amplified sound into the ear.


More sophisticated models provide additional features, such as direct connection to a smartphone or neural networks.


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Types of Hearing Aids


There are two basic styles of hearing aids depending on the choice of the user and the kind of hearing loss:

  • Behind-The-Ear (BTE)

    • Receiver-In-Canal (RIC)

  • In-The-Ear (ITE)

    • In-The-Canal (ITC)

    • Completely-In-Canal (CIC)

    • Invisible-In-the-Canal (IIC)

We illustrate them in the sections below.

Many of these hearing aids are

  • digital

  • rechargeable

  • supported with Bluetooth connectivity

  • enabled to provide tinnitus relief

What is tinnitus?

Tinnitus is when you experience ringing or other noises in one or both of your ears. The noise you hear when you have tinnitus isn't caused by an external sound, and other people usually can't hear it. Tinnitus is a common problem. It can be high-pitched, deep, low-pitched or even a tone that changes. It affects about 15% to 20% of people, and is especially common in older adults.

Further, technology-wise there have been two types of hearing aids:

  • Analog hearing aids work using older analog technology where they collect all sounds from the environment, increase its volume through an amplifier and present it to your ear. They are designed with a particular frequency response based on your audiogram. The audiologist tells the manufacturer what settings to install. Although there are some adjustments, the aid essentially amplifies all sounds (speech and noise) in the same way. This technology is the least expensive, and it can be appropriate for many different types of hearing loss.


However, these models have fallen out of favor as they are sometimes too loud and amplify both speech and noise, leading to poor speech clarity. Hence, we do not cover them here.

  • Digital hearing aids convert sound waves into numerical codes similar to computer codes, then amplify them. The code includes information about the direction of a sound and its pitch or volume. That makes it easier to adjust the sound to what you need, whether you’re in a restaurant, a quiet room, or a stadium. Digital hearing aids are usually self-adjusting.

Digital programmable hearing aids have all the features of analog programmable aids but use digitized sound processing (DSP) to convert sound waves into digital signals. A computer chip in the aid analyzes the signals to determine whether the sound is noise or speech. It then makes modifications to provide a clear, amplified, distortion-free signal.

The digital technology is the most expensive, but it offers many advantages. Key benefits include:

  • Improvement in programmability

  • Greater precision in fitting

  • Management of loudness discomfort

  • Control of acoustic feedback (whistling sounds)

  • Noise reduction

These aids are more expensive than conventional analog hearing aids. However, they generally have a longer life span and provide better hearing for you in different listening situations. We discuss several of them here.


A class of hearing aids works on the principle of bone conduction, that is, the conduction of sound to the inner ear primarily through the bones of the skull, allowing the hearer to perceive audio content without blocking the ear canal.

A BAHA is a surgically implanted auditory prosthetic based on bone conduction. It is an option for patients without external ear canals, when conventional hearing aids with a mold in the ear cannot be used. The BAHA uses the skull as a pathway for sound to travel to the inner ear. For people with conductive hearing loss, the BAHA bypasses the external auditory canal and middle ear, stimulating the functioning cochlea. For people with unilateral hearing loss, the BAHA uses the skull to conduct the sound from the deaf side to the side with the functioning cochlea.

BAHA can be non-surgical or surgical. Individuals under the age of two (five in the USA) typically wear the non-surgical BAHA device on a Softband. This can be worn from the age of one month as babies tend to tolerate this arrangement very well.

Surgical BAHA follows a simple surgical procedure with very low risk.The BAHA does not restrict the wearer from any activities such as outdoor life, sporting activities etc. and can be connected to an FM system by attaching a miniaturized FM receiver to it.

Leading brands of BAHA include Cochlear BAHA, Oticon Medical Ponto, and Medel ADHEAR.

A likely pathway to choose a hearing aid

Structure of a Human Ear

What's new in Hearing Aids

With digitization, hearing aid technology has evolved by leaps and bounds and grown to encompass technological developments in the other spheres of the patients’ lives such as mobile phone technology and AI. The following are some of the latest features you can expect in your hearing aids. And there are many more actually.

  1. Bluetooth Connectivity: Hearing aids now stream music, videos or video-calls from your mobile directly to your ears just like Bluetooth earphones.

  2. Rechargeability: Rechargeable hearing aids come with a charging dock and built in Lithium ion Batteries (just like in your phone).

  3. Apps and Smartphone compatibility: From basic Apps that allow the Hearing Aid user to control volume and change programs to more advanced ones that learn your routine and allow you to fine tune your Hearing aid programs (including features like noise reduction and feedback), and showing percentage of charge in your rechargeable hearing aid, are now available for both Android and Apple devices.

  4. Remote Programming: It may not be possible to perfectly program your hearing aid for all the various listening environments you frequent in your daily life, and it might not be feasible for you to travel to the clinic for multiple fine tunings. In such cases, we can enable a feature called remote fine tuning that allows the clinic to tune your hearing aid wherever you are called Remote Programming (wouldn’t it have been a boon during the lockdown?)

  5. Geotagging: Home, school or work are very different listening environments, and you may find that you change your volume and noise reduction settings every time you visit these places. With Geotagging, your hearing aid can track you through GPS and learn to shift to your preferred settings automatically, depending on your location.

  6. Find my Hearing Aid: Through the find my hearing aid option, you will be able to locate your device using your phone whether it is in your house or elsewhere.

  7. Binaural Sound Processing: Our ears are designed to work together and the brain compiles this binaural information to get a sense of our environment. Binaural sound processing in hearing aids involves the intelligent exchange of key listening information between the two hearing aids to create the most natural listening experience possible.

  8. Accessories: To make your listening experience even more comfortable, hearing aids are compatible with several accessory devices. For example, a device that directly streams sound from the TV is a popular one, especially with the elderly. For children (or professionals who attend meetings and conferences) who may frequently be in noisy environments like classrooms, a device that directly picks up the speaker’s voice and streams it to the hearing aid through Bluetooth does wonders in terms of improving speech understanding ability.


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Parts of a BTE

Parts of a ITE

Other Hearing Aid Parts

  1. Ear-Hook/Tone-Hook: The clear tube that connects to the receiver and loops over the top of the ear in BTEs

  2. Hearing Aid Battery: The power source for the other hearing aid components.

  3. Vent: Allows for airflow and prevents the feeling of a plugged-up ear.

  4. Volume Control: Allows the user to make adjustments to the intensity of the sound.

  5. Wax Guard: A small replaceable filter that prevents earwax from getting into the internal components.

Main Parts of Hearing Aids

Regardless of the style of hearing aid, whether it's a behind-the-ear or a completely-in-the-canal, they all have the same three main components:

  1. Microphone


The hearing aid microphone is the start of the process to help you hear better. The microphone picks up the different sounds in your environment and converts them to electric signals that can be understood by the processor. Microphones are now able to differentiate sounds, such as speech and background noise, and process them differently for a much more seamless hearing experience than in the past.


There are two types of microphones: directional and omnidirectional. Directional microphones pick up mostly sounds in front of the wearer. This can be helpful when trying to understand a conversation in a noisy environment. Omnidirectional microphones pick up sounds from all directions, helping to give the user a better sense of where sounds are coming from. Most new hearing aids come equipped with both types of microphones to help wearers pick up speech from multiple directions, creating a more natural listening experience.

  1. Processor/Amplifier


The processor or amplifier can be viewed as the computer or motherboard of the hearing aid. It takes the electric signals received from the microphone and converts them into digital signals that can be manipulated.


It's during this step that the sound, now a digital signal, is adjusted to the wearer's requirements, including how much the signal needs to be amplified to effectively accommodate the person's hearing loss. Any feedback or noise from wind is cancelled or reduced. This is also where any tinnitus masking features would be added.


Once all of the appropriate adjustments have been made to the digital signal, the processor then converts it back to an analog signal. It's here when the signal is sent to the third and final hearing aid component.

  1. Receiver


The final component in the process is the receiver. It creates an enhanced soundwave that will meet the hearing loss needs of its wearer. In order for this to happen, the receiver must convert the signal sent from the processor to audible sounds and output it to the wearer's ears.


The receiver is the piece of the device directed at the wearer's inner ear. Some hearing aids have the receiver placed directly in the ear canal, such as with a completely-in-the-canal style. Other devices have the receiver connect to a small tube that's inserted into the ear, like with the behind-the-ear style.


The complexity and the sophistication of modern hearing aid technology cannot be overstated. While it may appear to be a long process from start to finish, it's actually happening in a fraction of a second. It's through constant research and development that hearing technology continues to improve, and people with hearing loss can enjoy the most natural listening experiences possible.


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Behind-The-Ear (BTE)

In a BTE most parts are contained in a small plastic case that rests behind the ear; the case is connected to an earmold or an earpiece by a piece of clear tubing. This style is often chosen for young children because it can accommodate various earmold types, which need to be replaced as the child grows. Also, the BTE aids are easy to be cleaned and handled, and are relatively sturdy. The most familiar hearing aid style, BTEs, are housed in a durable case that rests on the back of the outer ear. BTEs are suitable for the widest range of hearing loss, including profound hearing loss. While the larger size BTEs allow for more power and features, the smallest ones, mini BTEs, are practically invisible when worn. BTEs are versatile devices suitable for a wide range of hearing loss, and are available in various sizes. The smaller BTE options are virtually “invisible” as they disappear behind the ear.

Features:

  • Sit behind the outer ear and comes in mini, standard and bigger size.

  • Fitting range : 30-120 dB

  • Requires larger battery (size 675, size 13,size 312)which provides longer battery life, rechargeable are option also available.

  • Innovation includes Bluetooth streaming, artificial intelligence, tinnitus masking features, advanced directionality.

  • Easy to hold, clean and adjust.

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BTE Hearing Aid

1 Hearing Aid Shell2 Ear Hook3 Microphone4 Rocker Switch 5 Left/Right Indicator6 Battery Door7 Manufacturer & Model 8 Charging Contacts

Pros

  • Size is easy to hold and adjust

  • Larger battery provides longer battery life - rechargeable options

  • Bigger size provides more durability and allows for more features

To Consider

  • Quick to fit (can take home the same day)

  • Least discreet hearing aid

  • Available in standard, mini or power

Behind-The-Ear (BTE): Receiver-In-Canal (RIC) / Receiver-In-The-Ear (RITE/RIE)

RICs are a type of open-fit hearing aid that use a thin plastic “micro” tube that extends from the body of the hearing aid (housed behind the ear) over the outer ear and into the ear canal. A small, soft tip sits inside the ear canal without sealing it. This way, air and sound can continue to flow to the ear canal naturally, reducing feelings of being "plugged up".


Receiver-in-the-canal (RIC) hearing aids - also referred to as Receiver-In-The-Ear (RITE) or Canal Receiver Technology (CRT) or Bluetooth hearing aids - are smaller than standard BTE models, but are easy to maneuver and can still house a variety of features. Like standard BTEs, they can be worn comfortably behind the ear. However, unlike regular BTE hearing aids, the RIC’s loudspeaker or “receiver” is located outside the housing and positioned at the end of a thin earwire, placed near the ear.


Features:

  • Smaller and more hidden than a BTE.

  • Best for mild to severe high frequency hearing loss (Fitting range upto105 dB).

  • Requires size 312batteries, rechargeable options arealso available.

  • Comes with latest technology like Adaptive directionality of microphone, feedback shield, binaural processing & synchronization.

  • Easy to handle.