German Institute of Hearing Aids
Funded and Joint Projects
The German Institute of Hearing Aids (DHI) is regularly engaging in research collaborations as a competent and reliable partner. This page lists research projects that were initiated by or in ocllaboration with the DHI and received external funding. The results of these projects are generally made publicly availabe and have the goal to increase the general knowledge in the field of hearing acoustics. Additionally, we offer our clients confitendial individual tests or industry studies, for which we can draw on a large set of experience from our research activities.
In all public and confidential test and research activities we assure that our neutrality and independence remains intact.
Optimized application of speech audiometry by evicence-based conditions in hearing clinics (OptiRaum)
Funded by: Innovationscommunity Hoerwerk, Bundesministerium für Bildung und Forschung / Datipilot
duration: 01.04.2025 - 31.03.2028
partner: Jade hochschule oldenburg
The aim of hearing aid provision is restoring communication abilities and participatation of hearing-impaired individuals in everyday life. Speech audiometry is a central aspect of the hearing aid provision process. The community project aims at providing an evidence-based foundation for application of speech audiometric tests in practice. Issues under research are room acoustics, loudspeaker setups and hearing aid processing - both using technical measurements and wuith human participants. The results will increase the accuracy of evaluating the hearing abilities, the benefit of a hearing device and the comparability of acquired data and in this way improve the quality of hearing aid provision.
Comparing hearing aid fitting strategies regarding preference and audiological outcomes
Funded by: Sonova
duration: 01.04.2025 - 31.10.2025
partners: Sonova
Hearing aid gain targets can be obtained using different prescriptive procedures, which mainly use the individual audiogram as an input. The procedure trueLOUDNESS additionally considers a measurement of the loudness function for a binaural, broadband sound, in order to achieve an individually better normalization of loudness perception in every day life. In this project, the preference and audiological outcomes with hearing aid fitting according trueLOUDESS are compared to those obtained with the standard Adaptive Phonak Digital 3.0 procedure.
The DHI conducts the project at own initiative and received funding by Sonova AG.
Individualised hearing aid fitting at high input levels
Funded by: William Demant Foundation
duration: 01.12.2024 - 31.05.2028
partner: University of Southern Denmark - Research Unit of Oto-Laryngology
The purpose of of this project is to investigate individualised hearing aid fitting at high input levels. To that end, research into characterising hearing abilities at above-conversational levels will be performed. Furthermore, several avenues for optimising aided outcome at such levels will be pursued.
The DHI pursues this project on own initiative together with SDU and receives financial support from William Demant Foundation.
Prevalence of increased binaural spectral loudness summation in the hearing impaired population
Funded by: Sonova
duration: 01.02.2024 - 31.07.2024
partners: Sonova, Acousticon, Hörzentrum Oldenburg
In this study, the amount of hearing-impaired individuals that show a so-called binaural broadband loudness summation. This effect regards the perceived loudness of environmental noises, which are often louder than desired, and was discovered quite recently. For Individuals with such loudness perception, hearing aid fitting can be stratified by the use of special procedures that exploit the individually measured loudness perception. The data of this study are acquired at the DHI, and at several collaborating healthcare professional facilities.
The DHI conducts the project at own initiative and received funding by Sonova AG.
Realistic hearing aid evaluation using virtual acoustics (AHEVA)
Funded by: german federal ministry for education and research
duration: 01.10.2023 - 31.03.2028
partner: Technische hochschule lübeck
The main goal of the project is evaluation testing of hearing aids in typical everyday situations both technically and perceptively in a reproducible way. This is enabled by using a virtual acoustic environment reproduced through a multichannel loudspeaker array. In contrast to existing procedures we pursue a novel approach, focussing on the ecological validity of the scenes and deriving technical and perceptualevaluation metrics from the scene itself. This provides new benchmarks for testing commercial hearing aids.
The DHI is a corporate partner within the project.
Evaluation of optimized earmolds designs
Funded by: Forschungsgemeinschaft deutscher Hörakustiker
Duration: 01.10.2022 - 30.09.2023
We evaluate specialized earmold designs that aim at reducing the occlusion effect im spite of a closed coupling. Such earmolds could avoid the usual compromise between comfort and natural own voice perception (usually achieved with open fits) and device performance (requiring a closed coupling) in hearing aid fitting.
Optical Hearing Enhancement
Funded by: German ministry of education and research
Duration: 01.10.2022 - 31.03.2025
Partners: medical laser centre Lübeck
In our project, the possibility of optical stimulation directly from the ear canal – as in classical hearing aids – is being investigated. Advantages over classical hearing aids with electromagnetic transducer are a higher, achievable bandwidth and the lack of need to close the ear canal. The project takes place in cooperation with Medical Laser Centre Lübeck GmbH and the Department of Otolaryngology of the University Medical Center Schleswig-Holstein (UKSH). The DHI is embedded in the project as a subcontractor.
Hearing Acoustics at the Belt (HABelt)
Funded by: European Union – Interreg 5a (Germany-Denmark), Network project
Duration: 01.07.2022 - 30.06.2022
Partners: University of Southern Denmark - Research Unit of Oto-Laryngology, Technische Hochschule Lübeck
We extend the international collaboration within the area of hearing acoustics and audiology between Germany (Lübeck) and Denmark (Odense) in a network project. The first goal is the development of a hearing aid demonstrator protptype, with the long-term goal to make the benefits of hearing aids more experiencable and contribute to better hearing support in both countries. Further details can be found on the project page
Direction-dependent Reference Curves for the Freiburg Monosyllabic Speech Test (RIBREFREI)
Funded By: BMWi WIPANO - Transfer of Knowledge and Technology by Patents and Standards
Duration: 01.09.2021 - 30.08.2023
Partners: Jade University of Applied Sciences Oldenburg
The main goal is to record standard reference curves for the Freiburg monosyllabic speech test in noise for different spatial arrangements of speech and noise. A special focus is the assessment of the influence of room acoustics on speech intelligibility in conditions where speech and noise are spatially separated.
Occlusion effect with variations of hearing aid coupling
Funded by: KIND Hörstiftung
duration: 01.10.2020 - 30.06.2021
For various individual earmold designs, the subjective and objective occlusion effect and further tramsmission parameters of a coupled hearing aid are determined. This allows to assess the compromise between the perception of the own voice and functionality of the hearing aid for different earmold designs, and to identify (non-) optimal designs for practical use.