Behind the schedule since 1989

BioAid Meets Life

Couple of weeks ago me and my wife went to a hearing aid center for a free consultation before, perhaps, buying a new hearing aid. The previous one has been working just fine for five years or more and it has became unusable lately. In the center they have run all the ususal tests, created an audiogram and offered a couple variants to choose from. I was satisfied with the devices, however I haven’t recognized any major difference from the one, that I already had. I was hoping to manage with $600-$500, and I was shocked when they named their price: even the cheapest of the devices was around $1000. We could afford it, but I declined.

Being a person with inborn defect of the auditory nerve, I’m wearing a BTE hearing aid all my life since the early childhood and I still remember the day, when I put the thing on for the first time. For a boy, who haven’t been hearing the sounds of footsteps on asphalt or the birds twittering, etc, it was a marvelous to discover all those sounds for the first time. Later in life, when I was wearing my fifth of sixth pair of hearing aids this wonderful piece of technology was already taken for granted and I was actively using it in school, university and later — in the workplace. Gradually, I started to recognize quite a few shortcomings of modern hearing aids:

  1. Most doctors would suggest you wear aids on both ears, since it is really good at helping you to locate the sound and experience the stereo or 3D hearing. Wearing two devices may be considered tempting if you don’t do anything else with your ears like using a phone, headphones and participating in all the different kinds of intense activities (sport?), when people may unwillingly flick it off. It’s a physical inconvenience of having something plugged into your ear that is not that simple to take off, but paradoxically simple to drop. People using them day-to-day would understand, what I’m talking about. Headphones and phone would also require you to take the aid off first and don’t get me started on the horrible phone regime, which is available in most modern aids. This was actually how I lost one of my aids: I needed to use a phone, took it off and missed my pocket. Never saw that device again.
  2. Whistling. Yes, they are constantly whistling and it is a curse upon the people with limited hearing. They whistle even more as the plastic ear mold of the aid is wearing off, which means that ideally it should be replaced every year. Whistling is produced by the mic and the speaker in the ear mold since they are too close to each other and the feedback sound is being produced. Ideally the ear mold should hermetically fit in the ear, to avoid the feedback, but at times it sticks out anyway, and when it does — it’s close to unbearable.
  3. Close sourced software and hardware parts. This industry is controlled by a bunch of electronics industry giants (Siemens, Phonak, etc) and they became to some extent monopolistic in this market, since only they had the initial resources to support research and production of hearing aids. Of course they are laying out all the rules now, which leads us to the fourth and the worst limitation of all.
  4. The price. These devices are pricey as hell. It’s a mic, a little processor and a speaker. Yeah, the size is super-small, but it doesn’t add up to $1500-$2000 in my head, sorry. It’s just immensely overpriced. I’m not a cheap guy, but I do have a problem when people feed me up with “magic” and as I work in technology, I know that such claims are almost 100% marketing and outright bullshit. They know that most of us — the hearing impaired don’t have a choice and we’re forced to pay twice as much money for anything they come up with. If you look for the last ten years — they are going round in circles. Hearing aids haven’t seen any revolutionary improvement for decades, compared with the booming technology market in consumer electronics and it’s just sad.

Considering all the above, there is great demand for some open solution in the market. Something you could thinker with yourself and use as a temporary or permanent substitution for a commercial hearing aid. To achieve that, it should be capable not only of recording, amplifying and reproducing the sound, but it also should be smart enough to amplify only some frequency ranges, depending on type and severity of the hearing damage. It would need some computational power to process the sound. Ideally, it should also analyze the sound and get rid of background noise, while normalizing the rest of it (making it quieter or louder depending on the context). Modern smartphones are perfect candidates, since they have everything we need in a hearing aid. I started looking for solutions available as an iPhone app and stumbled upon BioAid.

BioAid is an app, implementing a full-featured hearing compensation algorithm, developed by a team of scientists in the university of Essex. They themselves stress on the fact, that this is not about an iOS app, but the algorithm at the heart of it, which took years of research and continues to evolve today.

Initially, the research was not concerned with hearing aids at all but with the construction of computer models of how hearing works at a physiological level in the auditory periphery.

However, the team has moved to working on hardware models and opted for mobile phones, since commercial hearing aids are almost impossible or too expensive to modify and require an agreement with the manufacturers, which is not that easy to obtain. Smartphones have everything, that a hearing aid needs (a mic, a processor and a speaker), they’re compact enough and modern smartphones have sufficiently long battery life to perform on-the-fly sound processing almost all day. In my case it was a godsend and I rushed to test the app in everyday situations.

First thing I needed to do was to find the most suitable mode. For me it was simple since I’ve done million audiograms and knew that my hearing lacks some of the higher frequencies. After a quick scan I have found Gradual HF mode — the one I recognized at once as it reminded me of how all my aids sounded. My advice would be to start your scan with the first variants of every mode since some of the modes may be too loud or high in frequency and it’s just unpleasant to learn it the worst way. Surprisingly, finding the right mode is not a problem at all. I was afraid the app would require audiograms and it would complicate things. It’s definitely easier this way. Depending on the headphones (they have different levels and may alter the sound a little bit) I was best off with the 2nd and 3rd variants of Gradual HF mode.

I started testing the app in a park with lots of people walking, rolling and skating around. Although it was quite a test to start with I was pretty impressed with the results. It reminded me of times, when I put my first aid on. I heard everything happening around quite distinctly. Frequencies were altered in the right way. Sure iPhone headphones mic has its problems and I’m still hoping to find a better one, but other than that, I had no problems at all. It does reduce a little bit of background noise, depending on Gate value, however I wouldn’t recommend setting it much higher than default settings as it may cripple the other, more critical sounds. The problem with the standard headphones mic boils down to missing out on sounds from behind or on the left (if you have the mic on your right side) occasionally, but it’s not critical. However, if you’re speaking with someone and the person is on the left — it may work a little less precisely than usually. The mic is also quite sensitive to wind and clothing rustle. Due to some lag you can’t use Bluetooth headphones, though. This is an iPhone issue since people watching videos with Bluetooth headphones sometimes notice that too.

Usually, I wear my hearing aid in office, since it is the only place, where most of conversations are critical and may happen almost spontaneously. I was also quite satisfied. I heard everything said on meetings, even better, than with my previous aid, and decided to use BioAid at least temporarily at work. The only problem I can imagine is people’s perception of wearing headphones all the time. Some people assume that you’re listening to music. My office is quite liberal and modern since it’s an IT company and a little Skype chat announcement worked, I can imagine, however, it couldn’t always work this well. Me personally, I find headphones more aesthetically tolerable than a BTE aid, since people are almost constantly wearing headphones nowadays. Another problem is that you may need to buy a battery extender case or enhance the battery life of your iPhone in some other way. My battery is just enough to live through an usual working day, avoiding, if possible other uses of the phone. I only listen to some occasional music on my commute in the morning and after work. If I took the phone off charger at 8 in the morning it is usually almost dead by 22 after the full 8-hour day. Battery life is my biggest concern with the app so far. I had thought of getting a separate iPod Touch player and run the app there as professor Ray Meddis does in this video.

Other minor flaw is that algorithm is implemented in mono, though in theory, stereo implementation is also possible. It is a problem since it may affect your perception of the direction, the sound is coming from. Even if it was processed as stereo, the iPhone standard headphones mic is mono, so the sound is mono by default. Perhaps, stereo would be even worse as a battery drain, so maybe it’s OK the way it is. It is specific to iPhone implementation only and not the algorithm itself. Speaking about iPhone implementation, there are also some minor issues that complicate the workflow: like the app stopping on phone call and not resuming afterwards, or welcome screen appearing every time the app is launched, but all of these are solvable.

Still, for now I’m not even thinking of getting back to commercial aids. I have a very strong impression, that BioAid approach is the future of hearing aids. Especially for people, who don’t have the hearing damage so severe, that they require deep in-canal aids or even implants, which is majority of people with hearing problems. Unloading the sound processing from the aid to a smartphone or similar device (iPod Touch?) may be the right way especially considering the fact, that going from nine to twelve channels adds up at least a thousand dollars to the price of the commercial aid and iPhone has enough computational power to process much more. Sure, there are still some problems, but most of them are of the implementation and are going to be fixed sooner or later.

Algorithm itself is entirely open-source, which means you can fork it on GitHub and create your own version, addressing all of the issues described above, or providing support for some other platform. If you’re a hearing impaired person and you’ve decided to try BioAid for yourself, don’t forget to provide your feedback to the research group, since it may turn out very useful to them.

Update 14.11.2014: I’ve written another piece on BioAid in a year’s time, where I’ve reexamined most of my earlier observations and conclusions.