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Wireless Hearing
Hearing Loops and the Future of BluetoothGeschrieben von
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Staff
Veröffentlicht am Aug 18, 2021
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In today’s episode, we speak with two hearing aid experts to learn about wireless audio streaming in modern hearing aids. Today's hearing aids can stream multimedia and calls from your phone, but also have the ability to tap into shared audio streams through magnetic induction loops, or "hearing loops", which are installed in public spaces like auditoriums and churches. While hearing loops are the current state of the art, we'll also learn about the Bluetooth future of shared audio streams.
Today's guests include:
Steve Taddei: We all know that communication is easiest when we're standing next to someone in a quiet room. But that's not always possible. Many times we're dealing with this… [Noisy coffee shop]... When what we really want is this… [Audible barista]... Fortunately, there are many technologies that make this possible. In this episode, we're joined by Dr. Juliëtte Sterkens, and Andrew Bellavia to demystify the wireless technologies available and discuss what the future holds.**
Ad: Support for the HearingTracker Podcast comes from Nuheara. Nuheara is transforming the way people hear by creating personalized hearing solutions that are multifunctional, accessible, and affordable.
Steve Taddei: Can you hear me now? This is the Hearing Tracker Podcast from HearingTracker.com.
Juliëtte Sterkens: I felt a calling. I mean, it sounds crazy. But I felt that this was the thing that was gonna make my clients hear better.
Steve Taddei: That is Dr. Juliëtte Sterkens, an audiologist and strong lifelong advocate for people with hearing loss.
Juliëtte Sterkens: It was overwhelming, overwhelming for my patients. The experience, they would come into my office, that's what they wanted to talk about.
Steve Taddei: And what we are talking about here are hearing loops or hearing induction loops. These are a technology that can be used to improve audibility of sound sources that are far away.
Juliëtte Sterkens: So a hearing loop in its simplest form, is a wire that is installed in a facility. It could be in a church, a library, a meeting room, and the loop broadcasts the audio from the PA system wirelessly into the hearing aid if it's equipped with a telecoil.
Steve Taddei: And if you're not familiar with telecoils, or t-coils as they're sometimes called, they're just small receivers within hearing aids that allow them to pick up the wireless signal from a loop.
Juliëtte Sterkens: There is direct transference from the microphone of the person on the altar, or at the lectern, or from a play, direct into a hearing aid. In other words, the user hears sound as it was meant to be merely inches from the mouth of a speaker, of a presenter, of a minister and therefore hears sound at a very high signal-to-noise ratio. Very clear sound, no background noise.
Steve Taddei: Hearing loops are actually nothing new. They've been around since the 1930s. The wireless transmission provided by hearing loops and telecoils is made possible by something called the law of electromagnetic induction. It's also called Faraday's law, which comes from the inventor who first published the relation. Without getting too technical, any electronic device is going to put off an electromagnetic, or EM, field. Chances are you're bathing in EM fields like this right now. Faraday's law predicts that we can induce, or transmit, an EM signal onto a coil of wire. In fact, the sound you're hearing right now [electromagnetic interference] is an example of this process. By putting a microphone with a coil of wire by my speaker, I was able to pick up the EM field generated by my speaker's circuitry. And this is what we do for hearing loops, only the electromagnetic field is a desirable signal like speech.
You may be asking yourself, why would hearing aid users need hearing loops if they already have hearing aids in their ears?
Juliëtte Sterkens: Hearing aids really only work effectively in a range of about five or six feet. Now, it depends a little bit on the degree of hearing loss. If you have milder hearing loss, the hearing aid can provide better hearing and thus a little bit further range of hearing. But the more significant the hearing loss, the greater the residual hearing loss.
Steve Taddei: And this is exactly why we have wireless technology like hearing loops.
Juliëtte Sterkens: The Americans with Disabilities Act, the ADA, there's a law in this country that mandates that facilities offer wheelchair ramps, offer elevators, and have bathrooms that are big enough that wheelchairs can easily maneuver in. That law also mandates that assistive listening systems, assistive listening devices, are installed in places where PA systems are in use.
Steve Taddei: This means churches, movie theaters, and auditoriums are all supposed to provide assistive listening technology if you ask for them. Though we've been discussing hearing loops, there are other wireless streaming devices such as frequency modulation, or FM, and infrared, or IR, devices. All of these options work similarly. But FM and IR have certain limitations that we don't see with hearing loops. For example, they require you to wear a separate set of earbuds or headphones. There's also generally a body pack that houses the wireless receiver and batteries. A big consideration with these devices is that it is up to the facilities to maintain them and train their employees on their proper use. And that doesn't always happen. Another downside of IR transmission is that it requires line-of-sight. So if you were seated behind an obstruction, such as a pillar or large person, you may not receive a good signal. All of that aside, there is one other major benefit of using hearing loops.
Juliëtte Sterkens: The hearing aid is programmed for your hearing loss. That means the telecoil is also programmed for your individual hearing loss, and the sound from a loop gets then picked up by the telecoil in the hearing aid. So rather than the hearing aid microphone working, it's the telecoil that picks up the sound, it's a transducer. But what the hearing aid does with it is the same as what it would have done had it been picked up by a microphone.
Steve Taddei: If a venue uses only FM or IR, it doesn't mean that you're out of luck. The Americans with Disabilities Act, that Juliette mentioned before mandates that the system must have neck loop adapters for those who have hearing aids and telecoils.
Juliëtte Sterkens: In fact, just before COVID, I went to see Hamilton in the Oriental Theater in Chicago. And I always go to the service desk to find out what type of assistive technology they offer. And she started to offer me a listening device. I said, "Do you have hearing devices?" She said, "Yes" and she picked up a device with earphones. I said, "Oh." And she immediately said, "Oh, but we have neck loops." And I turned around and on the wall were at least 10 neck loops hanging on the wall. This woman knew exactly that hearing aid users and implant users need a neck loop to couple to the hearing aid. So then you pick up the device, you sit down in your seat, you can turn the device on, you don the neck loop around your neck. As soon as you've put it around your neck and the performance starts, you activate the telecoil inside the hearing aid. And now you have effectively looped your neck, your head, so to speak.
Steve Taddei: And if you go to a facility, and they don't offer any assistive listening devices, they're actually breaking the law.
While you can file a complaint through ada.gov, Juliette recommended a different approach.
Juliëtte Sterkens: I have found that these venues want to be accessible. They want to do what's right by their patrons. If you speak up, or you make an appointment with a theater manager saying “You know I've been coming to your theater forever, but I'm about to give up because I can no longer hear.” You're gonna find that you're gonna get cooperation. And if they have nothing and they have to start from scratch, my recommendation of course is that they install a loop rather than an FM or infrared system.
Steve Taddei: Whether you're an individual with hearing loss, or the owner of a facility, it can seem daunting to start the process of integrating a wireless listening system. Fortunately, Juliëtte and others at the Hearing Loss Association of America have made a toolkit consisting of PowerPoints, handouts, example letters, and even how-to's on finding companies to install these systems. If cost is a consideration, there are many situations where funding and grants are available.
Juliëtte Sterkens: I get emails from people around the country who say “I've heard about hearing loops, how do I get a loop at my facility?” They email me and frequently by applying for a grant these theaters are able to fund this technology, these installations.
We can overcome the limitations and that's really the message that I wanna get out. I want people to hear well with the hearing aids that they already have in their ears. So there's lots of listeners right now, who are wondering, do I have this t-coil or this telecoil in my hearing aid? If the hearing aid has a push button, there's a pretty good chance there's a t-coil in it. If it wasn't built in, they can get a remote control, or a little streaming device. It's not ideal, but it'll work. And the next time they're in the market for hearing aids, they ought to make sure they get a superfecta hearing aid.
Steve Taddei: When we come back from the break, we'll dive into another wireless technology that I'm sure you've used before.
Andrew Bellavia: It's the best possible audio quality you can get versus trying to listen to the speakers being picked up by the hearing aid microphones, and then the hearing aid microphones translating to corrected audio. It's actually one of the biggest benefits that I discovered in this world where we're doing so much online.
Steve Taddei: That's right, Bluetooth.
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With modern hearing aids, Bluetooth enables you to change the volume of your device from the palm of your hand [Volume beeps]. You can stream music, and you can even answer phone calls directly through your devices [Phone ringing and being answered].
There's a lot of magic going on behind the scenes making this possible. And not surprisingly, there are a few big changes right around the corner that will push the boundaries between hearing tech and Bluetooth even further. But before we get to that, let's start at the beginning and ask the question, what is Bluetooth?
Andrew Bellavia: Bluetooth was really developed originally to link mobile phones with earpieces so that you could have hands-free communications.
Steve Taddei: Andrew Bellavia is the director of market development at Knowles Electronics. He's also a hearing aid user. So he’s had a unique experience being on both the development and user side of hearing technology. I asked Andrew to help demystify Bluetooth, as there are many different protocols and uses.
Andrew Bellavia: Really, you can break it down to two different modes of Bluetooth. One is BLE or Bluetooth Low Energy. And that's a very low power consumption wireless communication protocol. That's used actually for data and control. It doesn't have the speed for audio. Then there's what people call today Bluetooth Classic, which is today's present audio Bluetooth, which is the audio stream used for phone calls and streaming music. And that one is two ways so that you can have a phone call and go in both directions. So I'll take my hearing aids, I have Phonak Marvels which are Bluetooth Classic hearing aids. If I take out my mobile phone and I change the hearing modes, it's a short burst of Bluetooth Low Energy that makes that happen. That goes between the phone and the hearing aids and tells them what to do. If I stream a podcast then it's Bluetooth Classic delivering the audio. Those are the two modes of Bluetooth today really that matter.
Steve Taddei: If you're a hearing aid user, you may have heard that audio streaming, as Andrew just described, is only available with iPhone devices. This was originally possible because Apple made an off-standard Bluetooth protocol allowing one way transmission. If you're not an iPhone user, don't worry because Android has since made their own protocol called ASHA, offering similar wireless functionality.
Andrew Bellavia: The advantages of all of these are that you're getting corrected audio delivered directly to your ears. That's much better than playing the audio on a speaker and having your hearing aid microphones, then pick up that audio and correct it for your ears. It's much easier to hear and understand and therefore a lot less fatiguing.
Steve Taddei: While we're on the topic of Bluetooth, I wanted to address a concern that I've been hearing from patients for years. And that is whether or not the wireless signal used by our phone in hearing devices poses a health risk. After all, these devices are sitting deep in our ears, and they often have to communicate with one another.
Andrew Bellavia: Really at the core of it is this, earphones and Bluetooth hearing aids are class two devices, which is a maximum output power of 2.5 milliwatts. So 2.5 one thousandths of a watt, it's pretty low power. The mobile phone itself can transmit up to two watts, so almost 1000 times more. So if you hold your mobile phone to your ear, you can have a couple of watts being delivered to your head. But if you use a Bluetooth earpiece, you've got a couple thousandths of a watt being delivered to your head. So relatively speaking, it's much lower power near your head when you're using a Bluetooth earpiece than the phone itself.
Steve Taddei: Andrew also went on to reiterate that our devices aren't always using Bluetooth. We mainly see them transmitting when we're streaming, and even then it is very low power.
Andrew Bellavia: Ultimately, what I would suggest people do is go to the American Cancer Society website. If you go there and just put “cell phones” in the search bar, you'll pop up a nice article that goes through all the research that was done, what different organizations say with links and so on.
Steve Taddei: I did exactly that. I visited cancer.org and typed “cell phone” in their search bar. There's been quite a few studies such as the 13-Country Interphone Study, the Danish Cohort Study, and others. All this research has not shown a clear link between cell phone use and an increased risk of cancer. A good reason for this is that RF, or radio frequency transmission, is a form of non-ionizing radiation. This means it does not have the ability to directly damage DNA inside our cells. That is however the connection to cancer that we see with stronger types of radiation, such as ultraviolet or UV rays. All that said, the American Cancer Society did acknowledge the limitations of the current studies. As a result, they do not have an official statement on the health effects of RF. That doesn't mean that you have to be worried and throw your phone in a tinfoil box. Some of these studies expose animals to extreme levels of radiation far beyond what we'd have as humans. And even those studies were deemed inconclusive. And to put this in perspective, we're talking about hearing aids and Bluetooth earpieces. As Andrew mentioned, the levels these devices transmit are far less than what you would get from other things like cell phones and towers.
Andrew Bellavia: If you have a Wi-Fi hub sitting near you, you could very well be getting more power being delivered to your body than a Bluetooth earpiece. And it's going all day long.
Steve Taddei: Let's bring this discussion back to Bluetooth and how it can help people with hearing loss. It's a great technology, but it's not without its limitations.
Andrew Bellavia: If you talk about what are the limitations of today's Bluetooth, the biggest one really is the power consumption. If you want an all day device, Bluetooth Classic consumes too much power. That's one of the big problems and the other is also the latency can be a little high. And that means there's enough delay in the Bluetooth streaming, if you're watching a movie, that the audio is slightly out of sync. Especially when people are talking with their lips, which for hearing impaired person can be a bit of a problem.
Steve Taddei: You may have run into this latency or delay problem before when streaming audio. For example, here I'm emulating a short delay of around 30 milliseconds [Short delay added to voice]. You shouldn't really notice much of a difference as our brains fuse the two signals to sound like one. However with Bluetooth transmission, we can see a delay, or latency, much greater than around 35 milliseconds. And when this happens it becomes very apparent, and we can start perceiving a clear echo between the two signals [Longer delay added to voice]. This can be very annoying. And as Andrew mentioned, it can cause sinking problems with what we see on our TVs. The final limitation of Bluetooth is that it currently allows for only one-to-one communication between devices. So unlike the hearing loop, we can't transmit a signal to multiple people, it has to be one transmission to one receiver. However, that is about to change.
Andrew Bellavia: Bluetooth 5.2, now you have low energy audio, meaning we're gonna transmit a two-way stereo audio stream with low energy. So you get that battery savings, just like you do with a proprietary MFI or ASHA. Now, it's gonna be a universal standard for low power music streaming or calls. And you have a broadcast mode, which is more like radio. So you have one transmitter, many receivers. In the broadcast mode, there's no transmitting going on in your ear pieces at all, they're strictly receiving.
Steve Taddei: This is great news for those of you who are concerned about RF radiation, your devices will no longer have to do ear to ear communication. They will each receive the stereo audio independently. So what other benefits will this new Bluetooth broadcast mode offer?
Andrew Bellavia: The broadcast capability of Bluetooth 5.2 will be in every true wireless earphone sold to consumers. I mean, maybe the cheapest ones won't adopt it, but it's there for everyone and you're gonna see most devices incorporate it. That means everybody, whether hearing impaired or normal hearing, is gonna have access to the broadcast capability. [Bar noise] Imagine I go to a sports bar, and there are 10 televisions. It's pretty cost effective to actually install a Bluetooth transmitter on each one of those. And so I could be watching a match over there and I can lock into the audio and listen to the audio.
Steve Taddei: This means anyone with a wireless device, not only those with t-coil hearing aids, will be able to tune-in and benefit from the broadcast. This could mean more people using it and therefore more facilities providing it for their patrons. So nearly everyone could experience the benefits, whereas it's only available now with hearing loops and telecoils. So what is a realistic timeline for Bluetooth 5.2 and true integrated broadcast systems?
Andrew Bellavia: Ultimately, this is going to take years. There are already true wireless earphones on the market that are Bluetooth 5.2 ready. But the software that goes with, and the protocols for broadcast mode, aren't ready yet. So let's say next year you start seeing devices that can handle the broadcast mode. Now in terms of broadcast Bluetooth versus telecoil, it's got to be 10 years out. I don't see telecoils going away anytime soon. Any hearing aid that puts Bluetooth 5.2 in can also add the telecoil for people who want it, you can have dueling systems for a while. What you really can't do is start taking telecoil systems out until virtually all of the telecoil only hearing aids have been flushed out of the market. And that's why I say I think it’s gonna be 10 years.
Steve Taddei: This is a very reassuring part of my discussion with Juliëtte and Andrew. You do not have to choose between induction loops or Bluetooth. They currently serve slightly different needs. And in the future, as differences between them blur, they should become more integrated into our devices offering wireless broadcast benefits for everyone.
Andrew Bellavia: The thing I'll end with, is the unexpected surprise of how good it works to have streaming directly to my hearing aids. I am much less fatigued or stressed having days of internet meetings, phone calls, and so on because virtually all the audio is delivered streaming to the hearing aids. It’s the best possible audio quality you can get versus trying to listen to computer speakers or your tablet speakers or what have you. And with the new Bluetooth standard coming, or even the proprietary systems available today for iPhone and Android, it's really something that if listeners who are hearing impaired are not doing today or audiologists are not really considering when you're working with your patients—I recommend you do because it is really one of the big benefits to always have streaming corrected audio whenever you're online or listening to a podcast.
Steve Taddei: I'd like to thank Dr. Juliëtte Sterkens for speaking with us about induction loops and how they can benefit people with hearing loss. If you'd like more information, you can visit hlaa.org and or hearingloop.org. You can also visit Juliëtte's website, loopwisconsin.com. I'd also like to thank Andrew Bellavia for sharing his insights on Bluetooth technology. If you have questions or would like more information, you can find him on twitter@AndyB_Knowles or on LinkedIn by searching Andrew Bellavia. The Hearing Tracker Podcast is hosted by me, Dr. Steven Taddei. Each episode, we reach out to people with hearing difficulty and or industry leaders to talk about the hearing system and innovative technologies like loops and Bluetooth. This episode was written, produced and sound designed by me with help from Abram Bailey, Bruce Smith, and TJ Belek. If you liked today's episode, please consider leaving us a review and share it with someone who needs hearing help. If you have a unique story related to your hearing, or if there's another show topic you'd love to hear, share it with us and send a line to Steve@hearingtracker.com. Finally, you can find much more helpful content and keep up to date by visiting us at hearingtracker.com. Thank you for listening.
