Audio Signal Enhancement

Signal processing and signal enhancement of speech and audio signals are among the main strengths of the Oldenburg Branch for Hearing, Speech and Audio Technology HSA. Tasks include the optimization of disrupted signals as well as the development of recording and processing technologies. This allows audiological data to be used for acoustic sensors even in a challenging environment, such as intense ambient noise. Apart from the enhancement of audio and speech signals the localization of sound sources as well as automatic speaker recognition are key research priorities for the Fraunhofer IDMT in Oldenburg.

In security applications, relevant sounds can be separated from less relevant ones by reducing background noise in preparation for acoustic monitoring. Specific examples are the recognition of breaking glass or the use of spray cans for combating break-ins and vandalism, but also the detection of drones. The reduction of background noise is a fundamental element of solutions in the area of speech recognition and voice control, for example in smart home applications or conference systems.

In addition, the design of personal hearing systems is enhanced through the individual reduction of the level of reverberation. Automatic volume regulation and the personalized adjustment of high and low signals ar other field ofs optimization. Both manufacturers of audio system equipment, multimedia devices or hearables as well as users with normal or impaired hearing profit. The localization of sound sources is a technology also used, for example, in the automotive sector for recognizing the direction of approaching emergency vehicles.

Our services

  • Single-channel and multi-channel signal processing for application-based sound adjustment
  • Processes for echo and background noise reduction
  • Directional filtering (beamforming) for the systematic recording of relevant audio data
  • Localization for detailed analysis of ambient noise
  • Microphoning and signal preprocessing
  • Embedding of signal processing in existing infrastructures
  • Integration of signal processing in mobile applications and new service models
  • Evaluation studies, e.g. technical evaluation of systems available on the market
  • Speaker Recognition
  • Extraction of a target speaker (Voice Filtering)

Christian Rollwage presents the voice filter technology

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Acoustically concentrating on one person in a large group can be a problem for people with hearing impairments. Christian Rollwage explains how our voice filter technology can help using audio examples. We have also presented the topic at the Tonmeistertagung last year. 

Subtitles are available.

Insights into research and practice


Press Information / 7.7.2022

Intuitive sound personalisation in vehicles

Everyone hears differently – this applies inside a vehicle too. That is why Fraunhofer IDMT in Oldenburg has developed a technological concept for fast and individual sound adaptation, which has been integrated into the multimedia system of vehicles from the Mercedes-Benz Group AG.


Press information / 4.11.2021

Better understanding

Tonmeistertagung 2021: Fraunhofer IDMT presents solutions for analyzing, evaluating and improving speech intelligibility


An insight into our research

Defense against drones

An interview with Christian Rollwage about »drone detection and localisation«. He talks about audio signal enhancement for emergencies.



Automatic Detection, Localization and Tracking of Birds and Animal Sounds by means of an Intelligent Acoustic Sensor System


Your sound, in every situation

Everyone hears differently. »YourSound« of Fraunhofer IDMT in Oldenburg enables users of audio devices to adjust audio to their own acoustic preferences – as easy as never before!


project website Fraunhofer FKIE

Drone detection and localisation

The high availability of drones opens up many new fields of application, but also threat scenarios, e.g. near airports and major events. In order to be able to react appropriately, security authorities need technologies for drone detection and localisation. In the AMBOS joint project, we are developing solutions for these challenges.


Press Release / 14.6.2016

Industrie 4.0 learns how to hear

In the joint project ACME 4.0, partners from industry and research will investigate the potential of acoustically monitoring machines and production processes. The goal is to develop an energy-autonomous, highly-integrated sensor platform that can be integrated wirelessly in industrial installations.


Flyer Audio Signal Enhancement

We analyse audio signals.

All solutions at a glance

Here you can find further information about our solutions of the Oldenburg Branch for Hearing, Speech and Audio Technology HSA.

R&D-Services and Licencing

Please contact us in case you are interested in our expertise and services.