New Study Shows Phonak's Roger Technology Enables People with Hearing Loss to Hear Better than People with Normal Hearing
Carolyn Smaka: Dr. Thibodeau, thanks for your time today. You recently published a study that showed that people with hearing loss using adaptive digital FM outperformed those with normal hearing (Thibodeau, 2014). Before we get into the details, tell me about the background.
Dr. Linda Thibodeau: A few years ago, we completed a study on adaptive FM versus classic FM in terms of speech recognition benefits (Thibodeau, 2010). Now that adaptive digital FM systems are available, it seemed to make sense to use the same protocol to look at the new technology.
In the current study, participants included 11 adults with primarily moderate-to-severe bilateral hearing impairment who used behind-the-ear (BTE) hearing aids, and 15 adults with normal hearing. The adults with normal hearing did not use any technology. We measured sentence recognition in quiet and noise in a very controlled environment, and we also obtained subjective ratings. We wanted to ensure that our results were applicable to the real world, so as we did in the previous study, we went to Dallas World Aquarium, which is very noisy. We had the participants judge the quality of the signal as we went through the different exhibits.
In the 2010 study, the participants were blinded to the technology. In the current study, the participants as well as the people who orchestrated the study and the people who did the scoring were blinded to the technology. As we started collecting data, however, it became obvious as the people using the adaptive digital FM technology performed significantly better.
One additional difference between the two studies was that in the current study we included testing at an 80 dBA noise level. In the previous study, most people were not able to get more than one or two words correct at an 80 dBA noise level, so we did not include it in the data analysis. We decided to try that level in the current study to see there were any differences with the adaptive digital FM technology.
The study was funded in part by Phonak and the adaptive digital FM technology used was their Roger technology.
Carolyn: What were the results?
Dr. Thibodeau: Performance with the adaptive digital technology was significantly better than with the other systems, with the greatest benefits at the highest noise levels.
People with normal hearing on average got 3 percent correct at the 80 dBA noise level, which is basically nothing. People with hearing loss were getting 48 percent on average with the new adaptive digital FM technology. It is amazing to me to think that we would be able to provide that much clarity for people with hearing loss in a very noisy environment.
And, with training or through a rehabilitation program, they could potentially even further optimize their use of the technology.
The majority of listeners in the study also preferred the adaptive digital technology when listening in the real-world noisy environment. Just think that in a noisy restaurant, someone using this technology may be able to hear better than his or her friends who don’t use any technology. This provides audiologists with a new avenue to increase services for people with hearing loss. This study changed the way I approach conversations for people who come into the clinic. Now, I think in terms of what network will work best. The conversation is no longer just about what goes on or in the ear. It’s about the person’s lifestyle and hearing challenges.
We have so many options with remote mic technology for interfacing microphones. For example, a clip-on microphone doesn’t add that much to the price of the whole package, especially if you start thinking in terms of a pricing structure for a hearing technology network instead of for just a hearing aid. In my opinion, it’s better to cut back on some of the bells and whistles on a hearing instrument and spend that money instead on a remote microphone system. There’s no digital hearing aid today that I know of today that can deliver the performance we saw in our study with the adaptive digital FM system.
Carolyn: Why did the adaptive digital FM enable such better performance?
Dr. Thibodeau: Good question. First of all, the digital transmission provides a much wider bandwidth for the signal transmission. This means that more information is transmitted across the frequency spectrum.
As you know, with FM systems, the microphone is close to the person speaking, and then that signal is delivered wirelessly to the receiver at a given intensity level. With adaptive FM, the microphone technology detects how much noise is in the environment, and based upon that, calculates the intensity level the signal (i.e., the speaker’s voice) should be delivered to the receiver. Once the level in the environment exceeds 57 dB SPL, the adaptive FM increases the intensity of the speaker’s voice over the background noise. Another way to say that is that the signal is presented at a greater signal-to-noise ratio (SNR). With adaptive FM, that range is 24 dB.
With adaptive digital FM, the SNR improvement is up to 30 dB, based on the noise level in the environment.
The third difference is reduced channel noise with the digital system. It’s a much cleaner signal. This fact was substantiated by the comments from participants, including: “Very clear and crisp”; “Voice much louder than the background”; “Even with the background noise I could understand more easily”; and “So clear, understood, really good.”
Carolyn: Those differences with the adaptive digital FM over the other systems help explain the results you saw at the 80 dBA noise level.
Dr. Thibodeau: Right. With adaptive FM, on average participants got 13 percent correct at the 80 dBA noise level whereas with the adaptive digital FM, they got nearly 50 percent correct. That’s because we are able to deliver a better SNR with the digital system.
Carolyn: You mentioned that you are using this technology with patients now. Tell me how that is going.
Dr. Thibodeau: Phonak has given us opportunity to use Roger equipment for the aural rehabilitation groups that we’ve been doing around the country, that we call SIARC (Specialized Intensive Auditory Rehabilitation Conference). We’ve been able to see how adults that were pretty comfortable with just using a hearing aid could expand their listening benefits by using a remote microphone. The group setting is an efficient way to orient them to this technology. We teach them how to use it and then take them out to dinner in a restaurant and they get real world experience and practice with it. In a typical clinic setting, if you train people in the office and then they take the technology home, they may forget how to use it, or leave it in the box.
Recently, at our clinic, we received a call from a gentleman in his 80s who qualified as a cochlear implant candidate because he wasn’t getting benefit from his hearing aids anymore. At his age, he wasn’t sure if he wanted a cochlear implant. He came in and tried the Roger system along with a new pair of hearing aids, and he loves the new system. I have a great photo of him at an assembly on Veteran’s Day with his grandson. In the photo, his grandson is holding the Roger Pen microphone. This is an example where Roger really leads in terms of technology. With his old hearing aids, a face to face conversation in quiet with his wife was very difficult, unless he knew the topic and could see her face. With new hearing aids and the Roger system, he could now go to a noisy assembly and talk with his grandson.
Carolyn: You mentioned that audiologists might consider packaging remote microphone technology as part of a total hearing solution. Is there any other advice that you could give for audiologists to help with the uptake of this technology?
Dr. Thibodeau: Yes, I think it is going to require a shift in our thinking. Remote microphone technology should not be viewed as an add-on to a hearing aid. For example, maybe you could offer three groups of options. Entry level one might be a clip-on microphone and basic hearing aids. Entry level two might be a Roger Pen to interface with cell phones, along with more sophisticated hearing aids.
Entry level three might be for the person who is actively involved in group situations. This would include hearing aids, a Roger Pen and a clip-on microphone. You could also suggest that they tell their family to purchase another clip-on for Christmas. Then, they can have multiple people with microphones in group situations, and hear interplay in conversations again.
I think the approach where we say, “FM can be added later – first see how you do with hearing aids” gives the wrong impression that hearing aids can do everything. Most people won’t take the time to come back and follow up, and may miss out on technology that can benefit them.
Instead, present the entire system up front. Ongoing group classes can provide reinforcement and opportunities for people to practice with their technology. Group classes are an effective way to get people to follow up as they may not always come in for an office visit during the trial period. Some people will say they don’t want to “bother us” and make an appointment if they have a question, but they may drop in to an ongoing group for help.
Another suggestion is to price a new hearing aid package to include one assistive device from a list. It could be from a category of alarm clocks, or phone solutions, or smoke alarms. Ideally, we want to provide a package that includes all of these things.
I compare the process of getting a hearing solution to that of buying a car. When you buy a car, you decide on your features up front. You don’t take the car home and then add features later on. The dealer describes the features to you and you make a decision based on your needs – do you want the anti-lock braking system? Do you want the upgraded sound system that adjusts its level based on road noise? I appreciate the salesperson that explains these features and makes recommendations based upon my needs.
We should think in terms of the total package that can benefit our patients. This approach involves really getting to know our patients and finding out their specific communication challenges.
Carolyn: The TELEGRAM can help with that.
Dr. Thibodeau: Yes, the TELEGRAM prompts you to probe the person’s communication challenges (Thibodeau, 2004). The acronym stands for those situations: Telephone, Employment, Legal Issues, Entertainment, Group Communication, Recreation, Alarms, and Members of the family.
It’s very quick to use. It gives you a great starting place to help select options and put together packages for your patients based on their communication needs.
Carolyn: You recently edited an issue of Seminars in Hearing on the topic of remote microphone technology. We’ll highlight these articles via webinars on AudiologyOnline in February.
Dr. Thibodeau: Yes, there are multiple applications of remote microphone technology in terms of different populations. In the issue of Seminars and in the webinars, we’ll cover using remote microphone technology with people who use cochlear implants; for students who have reading difficulties, have trouble paying attention or are on the autistic spectrum; and for people coming back from military service with traumatic brain injury. This technology can help many populations, not only those with hearing loss. In addition, there is application to infants with hearing loss. Remote microphone technology can make a difference early on with speech and language development.
Carolyn: You’re a passionate advocate of this technology and it’s been great having you share your research and clinical experience with us.
Dr. Thibodeau: It’s my pleasure. When someone gives me the floor to talk about this technology, I tend to get carried away.
Carolyn: Thank you! We’re looking forward to the upcoming webinars.
Thibodeau, L. (2004). Maximizing communication via hearing assistance technology. Plotting beyond the audiogram to the TELEGRAM, a new assessment tool. Special Issue: Assistive Listening Devices. Hearing Journal. 57(11), 46-51.
Thibodeau, L. (2010). Benefits of adaptive FM systems on speech recognition in noise for listeners who use hearing aids. American Journal of Audiology, 19, 36–45.
Thibodeau, L. (2014). Comparison of speech recognition with adaptive digital and FM wireless technology by listeners who use hearing aids. American Journal of Audiology, 23, 201-210.