Since few month, I'm interesting in hearing impairements and more specifically in hearing aids systems. When discussion around me comes about this project, two main legitimate questions arise:

  • What's wrong with the current systems available on the market
  • Why open source is so important

These questions are at the foundation of this project and need to be explained a bit more in details.

What's wrong with the current systems on the market

  • signal processing that could be improved
  • no control over your system
  • poor choice
  • social system not active

My first answer is "nothing is wrong with the actual on the market". Clearly manufacturers work hard and tends slowly to adapt their hardware to the technologies of today. Each company has between 20 and 200 engineers, researchers, technicians, audiologist and so on, therefore the price you pay can be understandable. Nevertheless, each product has its weaknesses and can be improved in several ways.

Of course, if I was thinking that everything is perfect, I won't think that an open source hearing aid would be beneficial for some users. When I digged a bit on that subject, I found a very interesting talk from Brian Moore intitulated improvements in hearing aids. The talk is now about 3 years old but the conclusions drawn are still valid (improvements on current signal processing, accurate performance measurements of an hearing aid, ...). In other words, there is plenty of room for an open source project to be beneficial on the matter. I invite you to watch the video (unfortunately, no transcription of the video is available at the moment).

These issues are met by any manufacturer open source or not. Nevertheless, the purpose of every compagny is to be profitable and by doing so, she needs to attract new clients and keep the old one. In order to do so, you need:

  • to be the only one on the market or have few competitors
  • have a good product experience
  • have a close system to avoid the client to switch easily to a competitor product.

This is a choice from the start, nothing is wrong with it as long as you have choices. This is one of the other purpose of the project: having the choice! It could sound painful by doing so, but having a different philosophical, technical approach can lead to very interesting outcomes, I just hope, it will happen here.

Another thing worth to be mentionned even if it's not related to the manufacturers is the social system in most of countries in Europe consider hearing aids as a system for comfort1 only (like for glasses) even if for the vast majority of people seeing and hearing "well" is more than a conmfort but a necessity. Because the prices of most hearing aids are really expensive (depending of the type of impairement you will pay between 300 and 3500 euros). This make the access of this system really difficult for most of people.

Usually when you enter into the audioprothesist shop, you'll have the choice between a very poor range of products and it will change from one audiologist to another. This is not the fault of the audiologists who have to make a drastic choice as they have to learn for each product how to calibrate it for the patient.

Why the open source is so important

Here, I'm going to describe the possible advantages that opening the sources of the project can bring.

First it can be obvious but it doesn't usually works like this in private compagnies, the potential users can take a complete part during all the life of the system, from the specifications to the use of the system. If you succeed by including the users all along the project, you increase the chances to get a product corresponding to the majority of your users. Having open specifications let everyone what is going on and choose the system based on all parameters. If there is a conflict inside the project or if the project stops, anyone can reuse the code (according to the license) in order to fork, improve, change to suit his needs. If a compagny close down, in the vast majority of cases, all information disapear with it. By opening the code and specifications you diminished the obsolescence. In the industry of hearing aids, the normal cycle of a product is that you won't have any updates of your system once it has been bought. Maybe there is a good reason to do so even if I don't see it but because everything is nowadays accessible remotely, any system should be updated regularly for at minimum reduces security holes. Having an open source project let as well anyone audit the code or hardware specifications, potentially ensuring that the system won't do anything not wanted (sending sensible information for example) or just discover or fix bugs.

Some work can be inspiring such as BioAid project developped at the University of Sussex but unfortunately stopped in 2013.

  • open specifications
  • potential direct link between the users and developpers
  • interoperability with other equipment
  • larger and better audit of the code and hardware
  • obsolescence diminished
  • update of the code
  • security regarding remote access of the device
  • control of the system by the user

  1. In France, the social security refund up to 60% until you reach a certain limit