Everything you wanted to know about hearing aids
Hearing aids are designed to amplify sound for those suffering from hearing loss and can greatly improve the quality of life for people with both severe and mild hearing impairment. These innovative devices have come a very long way since Malzel's ear trumpet and transistors.
The basics
What is a hearing aid?
Hearing aids are devices that amplify sounds so they can be heard by people with hearing loss. These days, they are small, unobtrusive, and technologically sophisticated, but they do have their limits; they cannot completely restore hearing no matter their quality.
The nuts and bolts
How do hearing aids work?
All hearing aids work on the same general principles: A microphone converts sound to an electrical signal, an amplifier increases the signal’s strength, and the signal is converted back to audible sound for playback from a speaker near or within the ear canal.
Kinds - What types of hearing aids are there?
- Completely in the canal, or CIC :
CIC devices are prized for being the smallest and least-visible type of hearing aid. They are well-suited to people with mild to moderate hearing loss. CICs don't have much problem with wind noise, but their compact size has drawbacks: they use the smallest hearing aid batteries which need to be frequently replaced. These aids can also get clogged with earwax.
- In the canal, or ITC :
ITC devices sit just within the ear canal and are visible to other people. ITC hearing aids must be customised to the wearer's ear for a proper fit but are useful for people with varying levels of hearing loss. Although they are not as small as CICs, they are compact enough to have tiny batteries that need to be changed more frequently than larger devices. They can become clogged with earwax, but offer more features than CICs, such as easily accessible volume controls.
- In the ear, or ITE :
ITE hearing aids are also customised to their wearers, and there are two versions: the full shell and the half shell. The former covers the entire ear bowl while the latter only covers the bottom half. Designed for people with substantial hearing loss, these slightly larger devices have batteries with a longer life than more discreet alternatives. Their speakers may become clogged with earwax, but the larger size is often seen as an advantage when it comes to additional features like easily accessible volume controls.
- Behind the ear, or BTE :
BTEs hook over the ear and have a tube that connects to the ear canal itself. These are for people with any level of hearing loss. They are larger than almost any other device, but the powerful amplification they offer is seen by many as truly offsetting the large size and susceptibility to wind noise. Still, their raw amplification power makes them a good choice for people who have severe hearing loss.
- Receiver in the canal (RITC) or Receiver in the ear (RITE)
In a RITCs hearing aid, a speaker is inserted within the ear canal and connected via a tube to an amplifier behind the ear. They are smaller than BTEs and can suffer from earwax clogging in the same manner as other devices designed for use deep inside the ear. As with BTEs, these devices are for people with severe hearing loss or those with mild or moderate loss but with a preference for this design.
Care
How to clean hearing aids?
Proper cleaning depends on the type of hearing aid you use, and you should follow the directions provided by the manufacturer. For designs that have components within the ear, first remove any built-up earwax from the device with a soft cloth or brush. You can use gravity to your advantage by holding the surface you’re brushing upside down, which helps debris fall away from the hearing aid. Clogged holes can be cleaned with small hooks, while most brushes from hearing aid cleaning kits have a magnet on one end to remove the battery if it needs to be changed.
Cleaning behind-the-ear designs is similar, except you can use warm, soapy water to clean the earmold and an air bulb to push water through the tube. Allow both to dry before using them.
Cleaning should be part of your daily routine. Every month or so, you should have your devices professionally cleaned. The pros have special vacuums and specially shaped brushes to remove stubborn bits of detritus.
Features
What are the most desirable hearing-aid features?
- Multiple channels: Having more than one or two channels allows you to switch if there is interference from other devices without losing efficacy.
- Directional microphone: Such a microphone can be directed at the person speaking or other source of sound that you want to hear.
- Noise reduction: Paired with speech enhancement, this consists of hardware programming within the device that can pick out speech and other desirable sounds while lessening the ambient noise.
- Feedback suppression:High-pitched squawks and squeaks can be painful to the wearer even if the person has hearing loss, so this is a welcome feature.
- Wind suppression: Adequate wind suppression seeks to make the sounds the device produces seem less like white noise and more like voice communication.
Are hearing aids compatible with mobile phones?
All mobile phones produced now must be hearing-aid compatible. There are four phone ratings, called M ratings, from level one to level four. The higher the number, the more likely it will be that the user can use the device with a hearing aid.
Because of the variable nature of hearing loss, some hearing aids come with telecoil antennas for their operation. If a user has such a device, then that person will need not only an M-rated mobile phone but also one that is T-rated. T ratings also have four levels, with one being the least and four being the most compatible.
