Assistive Listening Devices
Hearing aids are by far the most important way to avoid the complications of hearing loss. They do an excellent job of amplifying speech sounds and even include special DSP (digital signal processing) that helps them reduce background noise.
Even with the incredible features that modern hearing aids offer, it can still be difficult to follow conversations in some environments—especially when distance is a factor.
Some of the most challenging listening situations for hearing aid wearers include:
Hearing a speaker from afar.
Distance dilutes the energy of sound. The greater the distance, the less energy comes into our ears. If background noise is also an issue, which it usually is, it can be hard for our brains and our hearing aids to distinguish between desired sound and noise, when they are both coming in at a similar volume and from a similar distance.
Noise always makes it harder to hear the sound we want to hear, whether we wear hearing aids or not. While modern hearing aids help by suppressing noise, discerning between noise and speech becomes harder as the difference in volume between them becomes less—that is, when background noise is very loud!
In large, open spaces with hard surfaces, reverberation and distortion can become an issue. The reverberation from a speaker’s voice effectively becomes background noise, which can garble and confuse what they are saying. While many larger halls or rooms are treated to help absorb sound and prevent reverb from getting out of hand, some spaces will still present an issue. Gymnasia, churches, and even some lecture halls may pose a problem. Sparsely furnished rooms in the home can also create a similar effect.
In situations like these, where hearing aids may have difficulty identifying the desired sound, it can be impossible to identify the words a speaker is saying, even when you turn up the volume on your hearing aids. Additionally, you might cause hearing damage by boosting your hearing aids to such a degree, while still being unable to hear the desired sound.
This is where Assistive Listening Devices (ALDs) can help!
ALDs help people with hearing loss to hear better by reducing the distance between the desired sound and the ear. This allows people with hearing loss to listen, without disturbing others around them, to a more direct version of the sound they want to hear. In essence, ALDs make it sound as though a person across a crowded room is speaking directly into your ears!
Some ALDs work with hearing aids, while others can be helpful even if the person with hearing loss is not wearing hearing aids. However, they all work in one similar way: they create an electronic connection between the listener and the sound source.
The sound source might be a person talking into a microphone, or your television or stereo system.
A transmitter that encodes the sound and sends it to receivers is connected to the sound source. You can now receive that sound through certain types of hearing aids, or a dedicated headphone device. You can move freely around the space while always receiving the desired sound directly in your ears. This greatly reduces the strain of trying to listen from far away, and also removes the need to stay closer to the sound source!
Types of Assistive Listening Devices (ALDs)
Some ALDs are intended to work with hearing aids, while others work without them. Additionally, some ALDs will work with nearly any hearing aid, while others are manufactured specifically for use with one model of hearing aid, or some of the models from one manufacturer. The thing that ALDs all have in common is that they reduce the distance that sound has to travel through the air to reach you.
T-coils have been a common add-on feature for hearing aids for decades now, as they were originally intended to pick up the sound from a telephone’s speaker and transmit it to a hearing aid magnetically, rather than mechanically. This greatly improved the sound of the telephone for hearing aid wearers.
While Bluetooth has become an incredibly popular and useful way to connect hearing aids to a variety of devices, T-coils are still the method of connection for a variety of ALDs. Without T-coils, some common ALD systems will require an intermediary device to work with a set of hearing aids.
Loop systems are common in public spaces such as houses of worship, museums, theaters, lecture halls, etc. They work by sending an electrical version of the sound that is presented in the room into a loop of wire that runs around the perimeter of the space. Whether it’s a speaker talking into a microphone or the audio from a new Hollywood blockbuster, the loop system works the same way.
The signal from the loop system is then picked up by a T-coil, either in your hearing aids or in a stand-alone device with a set of headphones.
FM systems are perhaps the most common type of ALD. They work similarly to loop systems, but use radio signals to transmit sound from the source to a receiver device. Oftentimes, two types of receivers will be available: one with a small loop system that is worn around the neck, which allows your hearing aids to pick up the sound with their T-coils; and one with a set of headphones for non-hearing aid wearers, or those whose hearing aids are not fitted with T-coils.
FM systems are sometimes used interchangeably with loop systems, but are more common in smaller spaces where a loop system might be considered “overkill.” FM systems are great for meeting rooms, classrooms, restaurants, movie theaters, and more.
Infrared systems work nearly the same as FM systems, but they use infrared light to transmit the signal rather than radio waves. This means that in places where a lot of FM waves are in use, infrared systems can present audio with less interference and, ultimately, better sound.
Another aspect of infrared systems—which could be an advantage or a disadvantage, depending on several factors—is that their signals cannot pass through walls, as those from FM systems and loop systems can. They are commonly used in courtrooms for this reason, where privacy is essential.
Personal amplifiers are simply a microphone and amplifiers connected to a set of headphones. They make the sound louder in any environment. They’re often used in hospitals when a patient cannot wear their hearing aids. For those who do not yet wear hearing aids, they can also be useful for watching television, communicating in the car, or spending time outdoors. In general, a person who finds themself using a personal amplifier regularly should probably be wearing hearing aids, instead.
Amplified phones allow users to change the phone’s volume to suit their needs. Amplified ringers, T-coil compatibility, and portable amplifiers are also common features for these phones. While most of us use smartphones these days—usually tightly integrated with our hearing aids—an amplified telephone can be great for the times when you’re not wearing your hearing aids. For example, if you receive an emergency phone call at night, or want to talk to someone on the phone just before going to sleep.
If you have questions about ALDs or require a hearing test or hearing aids, contact us today! We look forward to supporting you on your journey to better hearing.
Hearing Aid Microphone
These are a popular and useful add-on for many hearing aid wearers. These microphones are usually made by the hearing aid manufacturer to work with their specific models of hearing aids. They will usually offer a few different varieties that may be more or less appropriate for different situations. These might include lapel mics, table-top mics, or handheld mics. They are useful for the same purposes as a personal amplifier might be used but have the advantage of an unwired connection, so they can work over longer distances, almost like an FM system.
Imagine being at a museum with your partner, where you want to be able to talk to each other at a low volume, and even when you’re not standing directly next to each other. Your partner can wear a hearing aid microphone on their lapel that will transmit the sound of their voice directly to your hearing aids at all times, making it much easier to navigate the environment together.