Revolutionary technology for hearing aids

The „Vibrosonic-Aktor“ is the first ever speaker in a hearing device that is developed using microsystem technology – and Vibrosonic is the name of the Mannheim startup applying this tech to develop high-end hearing solutions that can be worn invisibly. We met the two founders Jonathan Schächtele and Dominik Kaltenbacher for an interview in the medical technology center Cubex 41.


Hello Vibrosonic! What led you to develop hearing solutions? Is hearing impairment a problem you have experienced yourself? 

Dominik: No. It was a result of our work. We were both active in the  Fraunhofer task group for automation in the medical segment. And I had also started a project with the University of Tübingen in 2007, that aimed at developing an implanted hearing solution.

Jonathan: … yes. This was also one of my first projects when I came on board in 2009.

Dominik: That project formed a basis for our startup Vibrosonic. We developed a new type of piezoelectric speaker for hearing aids.

… which is very tiny?

Dominik: Indeed. The smaller model, intended for implantation is only around 1,5 millimeters in size. A variation of this, that is positioned onto the eardrum from the outside, is around 5 millimeters in diameter.


Developing: Dominik Kaltenbacher and Jonathan Schächtele


Though this is not the entire system, but only the speaker?

Jonathan: Exactly. There are more components. Also, we are focused on two separate products, which must be seen individually. The module for the auditory canal includes an amplifier and electronics that take care of data processing, as well as a battery and microphone. Our second product is an implant. As a result the Vibrosonic-Aktor is as small as possible and is positioned right at the intersection of middle and inner ear. In addition to this there is an electronics module that is implanted below the surface of the skull. This product is a cooperation with a large hearing aid manufacturer, and we are in charge of supplying the tech.

So I can’t buy a hearing aid from you directly?

Dominik: You can. Our „hearing contact lens“, as we like to call it, is a classical hearing aid, which uses a speaker that is put onto the eardrum. The device is worn deep inside the ear canal to make it virtually invisible. This offers two advantages to current hearing aids: For one, you can’t see it. And secondly our product can transmit frequencies of up to 16.000 Hertz (high pitch sounds), as it is positioned directly on the eardrum. Other products range no higher than eight to ten kHz in amplification. The higher frequencies are very important for directional hearing and language comprehension though. To be able to pinpoint and follow a singular voice in larger group of people is something directly connected to these high frequencies. So the technology offers a lot of benefits. However we still have to prove these benefits in the lab. But all of our laboratory measurements to date suggest that we are right.



And you do your own marketing?

Jonathan: Correct. It’s 100% our product and will be promoted as a Vibrosonic brand product. For the other product, the implant, we function as component manufacturers and developing partners. Our partner, a large-scale manufacturer of cochlea implants, is in charge of finalizing the product and distribution. So we have both a b2c and b2b model.

Can I buy a Vibrosonic hearing aid today?

Jonathan: Not quite yet. We are aiming for launch in 2020.

That’s quite the wait!

Jonathan: Yeah. It’s a long process. Our research projects that had slightly different goals begann in 2008. Back then we had the plan to develop a middle ear implant, to help people that were almost completely deaf, by stimulating the the middle ear electrically. In the course of the research work we then discovered a much larger potential.



To create a tiny piezoelectric speaker for example?

Dominik: The innovation lies in the fact we are using microsystem technology, which comes from the development of computer chips. Where one would once use a cutter and drill, we now apply light and chemical processes to create the structures. This allows for much smaller systems to be developed, that still offer high levels of performance. This is a technology shift, as current hearing aids operate with normal speakers that use wound-up spools. We are able to produce many speakers simultaneously from silicon slices.



The basic principle transforms acoustic signals into electrical signals, amplifies these and puts them through the speaker, right?

Jonathan: We etch the silicon to produce a cantilever. We have two layers of different materials: one is rigid , the other can deform when exposed to an electrical current. This achieves an expansion and contraction. As the piezoelectric material is attached to the rigid  material, the whole membrane will bend upwards or downwards.

And as with any speaker this creates an oscillation of air, which creates an acoustic signal? And this membrane is capable of oscillating up to 16.000 times per second … so with up to 16.000 Hertz?

Dominik: Bingo! And to make this happen we require complex process technology and clean-room conditions in production, as the parts are so small that even a tiny contamination will shut everything down. At the moment we are building our prototypes at the Heidelberg Innovation Lab. Additionally we are cooperating with the École Polytechnique Fédérale de Lausanne (EPFL).



Is Mannheim a potential production location?

Dominik: Yes. We want to start production in the new medical technology center Cubex One, that is currently being built. A whole campus in being created there around the Mannheim University Hospital. Cubex One opens in 2019, which suits our planning schedule. First of all, financing must be taken care of though … as a clean room is quite expensive.

Could a clean room be shared and become a form of advanced co-working?

Jonathan: That would be interesting for us, in order to distribute the financial load. But we haven’t found a suitable partner yet.

What makes Mannheim a good fit for startups in medical technology, such as Vibrosonic?

Dominik: We both worked at the Fraunhofer Institute for Manufacturing and Automation in Stuttgart. In 2011 the institute created an external branch in Cubex41, in Mannheim, for production technology and automation in Biotech. Vibrosonic was later created as a spin-off. Along with Fraunhofer we have the University Hospital Tübingen on board, where everything started. In the meantime we have built a great relationship with the ENT-department of the university hospital in Mannheim.

But you started up as a team of three?

Jonathan: Yes. Together with Dr. Ernst Dalhoff, who works at the University Hospital in Tübingen. A short while ago we employed a new colleague, and in 2018 we will welcome two more people from Fraunhofer to the team. At the moment we are looking for microsystem technicians, test engineers and quality managers, as our focus is currently still very research-intensive. We want to monitor our manufacturing process so that we can continuously optimize it. There is a lot of tech that has to fit in a very small space. We have to explore the limits of what is possible, both technically and financially, and we must find the optimal production technology.

Dominik: And also just as important is securing financing. In June we  completed a round of financing for 2018. Though it is still a long way till we reach market maturity, and we must secure financing for the whole ride. We have Auric Hearing Systems on board as a strategic investor, who are a great partner for distribution.



What are the advantages of working at Cubex 41?

Jonathan: There are other startups here to exchange views with. Fraunhofer is here, which is very good for us. These cooperations are very important for us, as we can use the the Fraunhofer Institutes equipment. This location is super for the transition phase. And in a few years we will hopefully be part of Cubex One.

What is your experience with the startup scene in Mannheim?

Jonathan: It’s quite vibrant! There’s a lot going on, and things are still growing all around.



What do you enjoy about being your own bosses?

Dominik: The great variety of topics and approaches, that one has to take into account. In a start-up everyone has to do a bit of everything. This helps you discover your own potential, and you just learn so much. Setting up a business involves a lot of red tape, but we definitely know why we’re doing this!

Interview: Paul Heesch / LA.MAG

Photos: Ricardo Wiesinger

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