Harnessing the Benefits of Signia’s New IX Platform with Real Time Conversation Enhancement
AudiologyOnline: Welcome, gentlemen. It's nice to have you with us here at AudiologyOnline. Let me start by asking when developing a new platform or feature, what are some factors you must consider before that new platform is brought to market?
Sebastian Best: First, we focus on what is best for the customer, who is the person with hearing loss. We need to ensure that we work on an issue or challenge that is relevant to the daily life of the hearing aid wearer. Therefore, we often conduct studies in an early phase of product development to ensure we are addressing the day-to-day communication needs of hearing aid wearers. Along the way, during the initial development of a new platform, we need to bring several competencies together, including engineering, marketing, and audiology, to ensure everyone works toward the same goal.
Brian Taylor: Clinicians might not realize that it often takes more than five years for a new platform with new features to go from the benchtop to the clinic. Besides taking a tremendous amount of resources from several divisions within the company, it requires some painstaking analysis of the market. We want to make sure we best capture the wants and needs of persons with hearing loss and what features might be most beneficial to them. Additionally, we want to thoroughly understand the challenges of clinicians who dispense our hearing aids. We want to create solutions that help them operate more efficiently when we bring a new platform to the market.
AudiologyOnline: Sebastian, since you are new to AudiologyOnline, I will direct this next question to you. Prior to IX, what are some other features you helped develop and bring to market for Signia?
Sebastian Best: I’ve been in the field for about 15 years, and it’s great to be with you. The first platform I was involved with was our Pure Bimax platform more than ten years ago. I was responsible for the audiological part of the feedback canceller.
Since that time, I have helped develop several new hearing aid features. Highlights for me include the Micon platform with an entirely new audiological architecture at the time, the Nx platform with the unique Own Voice Processing (OVP) feature, and of course – for me personally, the biggest one: Augmented Xperience (AX) technology. The AX platform, launched in 2021, is a new way to implement compression, directionality, and digital noise reduction into hearing aids. AX did this by splitting the wearer’s soundscapes into two hemispheres and processing each hemisphere independently.
Brian Taylor: If I could add, Sebastian provides a useful example of a feature created more than a decade ago that’s an essential component to any customized hearing aid fitting. In this case, adaptive feedback cancellation. Even though manufacturers don’t tout their feedback cancellers too much these days, it’s an essential feature. And we know that not all feedback cancellers are created equal. Please allow me to explain. One way to assess the quality of any feedback canceller is by measuring its maximum insertion gain before feedback. Shortly after our adaptive feedback canceller was launched, an independent study1 was published indicating that Signia’s feedback canceller enables an additional 30 dB of insertion gain before feedback at 3000 Hz in an open fitting. Given that most fittings these days involve a non-custom ear tip coupled to a receiver-in-the-canal (RIC) device, this finding should be peace of mind for audiologists who fit Signia hearing aids, knowing their patients are receiving adequate high frequency gain.
AudiologyOnline: Over the past couple of years, at least here in the US, Signia has become known for split processing. We are curious, how does split processing work? And what makes it unique?
Sebastian Best: With everything we do in the development of hearing aids, we want to overcome compromises. A prime example of this is Own Voice Processing (now OVP 2.0). We know the wearer’s own voice needs to be processed differently by the hearing aid compared to all other sounds. In the design of AX, we approached the problem in a similar way. That is, to bring the best listening experience to the wearer, we know that all the various sounds around us need to be processed differently.
Other platforms tailor the processing to an average in every listening situation. That’s the compromise we wanted to overcome with AX: Splitting the world in two and processing them independently of each other.
Brian Taylor: Let me try to elaborate. To really appreciate the unique and innovative aspects of AX, it helps to compare it to more conventional types of signal processing found in other prescriptive hearing aids. Let’s start with omni-directional processing. Of course, in an omni-directional system, the soundscape is processed as a single stream: essentially, all sounds in the single stream are processed in the same basic way. In contrast, in a conventional front-facing directional system, the gain for sounds coming from the back hemisphere of the wearer are substantially reduced relative to sounds coming from the front hemisphere.
AX’s split processing was a departure from these conventional approaches. AX splits the wearer’s soundscape into a front and a back hemisphere, and each hemisphere is processed independent of each other. In simple terms, if speech is detected in either the front or the back, more gain is applied to that signal.
AudiologyOnline: With the launch of the IX platform, how has split processing evolved?
Brian Taylor: We have moved from what we at Signia call a two stream system to one that is multi-stream. To learn more about the sophistication of IX, I would encourage readers to download and read our recent IX white paper. You can find it here. For some of the technical details, from more of an engineer's perspective, I’ll turn it over to Sebastian. Since he was one of the creators of split processing, he can explain some of its intricacies.
Sebastian Best: Happy to, Brian. With IX, we have unleashed the idea of multi-stream processing. The basis for AX was something we understood very clearly from our research -- that persons with hearing loss are still able to focus on distinct sound sources within noisy environments if we make sure that we enhanced the contrast between all sounds around them. This is what we mean if we say, we augment the sound.
Now, in IX we can do that with much finer granularity, tailored to some of the most important conversation scenarios: group conversation. In the front hemisphere, we can augment multiple speakers at the same time to differentiate them from each other as well the background noises. The system detects multiple speakers in front of the wearer and knows their position very precisely. And even if the wearer rotates his head, the system is extremely fast and can keep the position stable by updating these data a 1000x per second.
AudiologyOnline: I see that a core part of the IX platform is Real Time Conversation Enhancement. Could you tell us more about Real Time Conversation Enhancement (RTCE)? I am curious to know where the motivation for developing RTCE came from?
Sebastian Best: Audiology is filled with an abundance of research on speech intelligibility in all types of situations but almost nothing about the behaviors and dynamics of real-life conversations. But it is these fluid, improvisational, spontaneous conversations that truly matter in the end – hearing aids need to enable people to be brilliant conversation partners again. To accomplish this task, there is much more needed from hearing aids than improving speech intelligibility. We found in our preliminary research that there are not even criteria to judge the quality of conversations in a holistic way. So, we started several research initiatives to change that. We investigated new study designs to simulate a real conversation.
Brian Taylor: Signia invested a considerable amount of resources into trying to better understand the elements of successful conversations, the technical mechanics that underly conversations 2,3, and finally, how IX hearing aids can more effectively address these conversational dynamics. I think there are three key findings that come from this research, Sebastian mentions, and all three were applied to the development of the IX platform.
First, success in conversations is more than hearing ability; it is about the ability to actively contribute to the conversation. Hearing aids help a person reconnect and contribute to these spontaneous interactions in a meaningful way. Second, hearing aids do more than help people hear, they improve turn-taking and speaking levels of conversational partners. Third, using hearing aids results in improved conversational behaviors. When a conversational partner with hearing loss is provided hearing aids, they behave more like others in the group who have normal hearing. With IX, we have designed a hearing aid that helps a person reconnect and more actively contribute to any conversation.
AudiologyOnline: Could you provide us with some details on how RTCE enhances or improves split processing?
Sebastian Best: As I said earlier, IX can enhance talkers who are in a group conversation. An interesting point is this enhancement is not the same as traditional directionality.
Proximity to the wearer is part of the equation in IX. That means not just talkers that are close enough to you are enhanced – speakers from the same direction but farther away not. That helps the wearer even more to focus on the actual conversation and reduces listening effort.
Brian Taylor: We published a recent benchtop study demonstrating a 4 dB SNR improvement from XI when compared to premium RIC devices from four leading competitors. In this study, we measured SNR at the output of the hearing aid on the KEMAR using a phase inversion technique commonly found in hearing aid research. In our study design, speech originated from two locations in the frontal hemisphere of the wearer in a way that simulated real-world conversation and speech-like noise originated from two locations in the rear hemisphere. It’s important to note that four of the five brands of hearing aids showed at least 4 dB of SNR improvement from the unaided, open ear canal baseline condition.
Remarkably, as shown in Figure 1, Signia’s IX provided an additional 4 dB of relative SNR improvement compared to the other devices assessed in the study. We believe the added 4 dB of relative SNR improvement from IX is this scenario is attributable to the Real Time Conversation Enhancement (RTCE) feature, which identifies and amplifies speech in three separate frontal focused acoustic snapshots. I encourage everyone to read the details of this benchtop study for themselves by accessing the white paper here.
Figure 1. Output SNR of hearing aid output for five hearing aid brands compared to the KEMAR open ear baseline condition. Study design details can be found here.
AudiologyOnline: That’s an eye-opening finding. Let me ask a follow-up question related to the RTCE feature. I understand that RTCE technology is integrated into Dynamic Soundscape Processing (DSP) 3.0. I am sure our readers want to know a little more about how DSP 3.0 works. What should hearing care professionals know about how RTCE is integrated into DSP 3.0?
Sebastian Best: With IX, we take into account the conversation layout. For example, a conversation with more speakers is more complicated and demanding than one that is 1:1, independent from the wearer’s surroundings. By knowing exactly how many talkers are speaking to you – IX can take that into account and ensure the wearer gets optimal performance in any free-flowing conversation scenario.
AudiologyOnline: Let’s shift gears and talk about some other Signia innovations. Signia Silk is now rechargeable. How did Signia create such a small rechargeable hearing aid?
Sebastian Best: What our colleagues achieved here made us all really proud. Silk is such a unique product already with batteries, and for a long time, it was said by many there was no way to design a rechargeable CIC without increasing the size. But that was proven wrong – the Silk is still extremely small, fits into almost every ear, and is rechargeable.
It comes out of a very unique collaboration of electroacoustic and industrial design that made this possible.
You need people who can really think out of the box, are open-minded, and think always with the customer in mind.
If you look at the charging case, you will discover many details that are important. Like the small notches behind the pullout string – absolutely necessary for an older wearer to be able to remove the device safely.
AudiologyOnline: Signia has three innovative form factors: Styletto, Silk, and Active. Could you describe those form factors and why it might be important to hearing care professionals to offer them in their practice?
Brian Taylor: With these three form factors, we want to change how hearing aids are perceived by persons with hearing loss as well as the general public. In totality, these three form factors demonstrate that hearing aids can be invisible, they can be fashionable, and they can even by a little trendy. We also have some soon-to-be-published research, led by Andre Marcoux, one of our Canadian colleagues, suggesting that just by having these devices in the clinic and promoting them, new customers are more likely to acquire hearing aids.
AudiologyOnline: What other Signia features would you say fly under the radar - ones that are either unique or don’t get talked about enough?
Sebastian Best: I am personally a big fan of the Signia Assistant (SA). It’s a feature in our hearing aids for more than four years, and for the right wearer, it can empower them to be more actively involved in the wearing process. With the help of AI on the Signia Assistant, the wearer can get help in the moment to solve an individual hearing problem right on the spot.
That’s a big help for the clinician because it reduces the need for fine-tuning sessions based on difficult problem descriptions from the wearer.
AudiologyOnline: Thanks to both of you for spending some time with us.
- Marcrum, S. C., Picou, E. M., Bohr, C., & Steffens, T. (2018). Feedback reduction system influence on additional gain before feedback and maximum stable gain in open-fitted hearing aids. International Journal of Audiology, 57(10), 737–745.
- Nicoras R., Gotowiec S., Hadley L.V., Smeds K. & Naylor G. (2022). Conversation success in one-to-one and group conversation: a group concept mapping study of adults with normal and impaired hearing. International Journal of Audiology, 1-9.
- Petersen E.B., MacDonald E.N. & Sørensen A.J.M. (2022). The Effects of Hearing-Aid Amplification and Noise on Conversational Dynamics Between Normal-Hearing and Hearing-Impaired Talkers. Trends in Hearing, 26, 1-17.