Contact for the eardrum

April 30, 2020

Together with the TU Berlin, Fraunhofer IZM is developing a microbattery for a hearing contact – an extremely small hearing aid, that attaches directly to the eardrum.

© Vibrosonic GmbH
The hearing contact lies directly on the eardrum and thus improves the hearing quality.
© TU Berlin
The components of the hearing contact lens are integrated into a tightest-fitted volume.

By the age of 70, one in three people will experience a hearing loss of at least 35 dB (the volume of a ticking clock or a room fan) – and will need a hearing aid. However, due to the poor transmission of the air column in the ear canal, traditional hearing aids often cause feedback and distortion effects that make it difficult to hear and understand.

Minimization of disturbing factors

The hearing contact touches the eardrum. This direct contact between the eardrum and the piezo actuator, which is used instead of a loudspeaker, minimizes transmission errors and also allows the perception of a wider sound spectrum. Directional hearing is also significantly improved. In particular, this optimizes speech comprehension both in quiet and in ambient noise environments.

Microintegration for the middle ear  

The specially developed ultra-thin transducers and batteries allow the system components to be integrated in a very small space, so that the hearing contact is small enough for use in the middle ear. Once inserted, the system does not to be removed for a battery change. The batteries are charged by optical energy transfer. The demands placed on the micro-battery are extremely high: in addition to the high energy and power density (to enable rapid charging) of the battery, which is only 0.7 mm thick, 2000 full cycles are to be achieved. The concept of the hearing aid has already been presented at the MikroSystemTechnik Congress 2019 in Berlin and is currently undergoing clinical testing. CE marking is expected in mid-2020; market entry in Germany is planned for 2021.

Hearing Contact

In addition to the Fraunhofer Institute for Reliability and Microintegration IZM, the following partners are involved in the development of the hearing contact:

  • auric Hörsysteme GmbH & Co. KG
  • Fraunhofer Institute for Production Technology and Automation IPA
  • Research Centre of Microperipheric Technologies at the TU Berlin
  • University of Tübingen, ENT Clinic Tübingen
  • Vibrosonic GmbH