Individual sound quality and good speech intelligibility

What distinguishes good sound? Why are some sounds perceived as annoying? When does music sound “just right” to the individual? How can speech intelligibility be evaluated objectively and optimized in a needs-oriented way?

The “Personalized Hearing Systems” group at Fraunhofer IDMT in Oldenburg has answers to these questions. Based on findings from psychoacoustics and in close exchange with clients, partners and alliances, such as the Hearing4all cluster of excellence, IDMT’s experts develop computer models that simulate our personal hearing perception. This forms the cornerstone for intelligent hearing solutions that optimize sound experience individually for each listener. Because everyone hears differently well!

Individual and better hearing is defined – depending on the application – according to various sound parameters, such as speech intelligibility, listening effort, sound quality, loudness, harshness or annoyance.

Our services for you:

  • Development of application-specific signal processing methods and operating interfaces
  • Hardware development and optimization
  • Embedding of signal processing algorithms in hardware and mobile applications (apps)
  • Computer-based, psychoacoustic evaluation of sound quality and speech intelligibility
  • Perception models for various sound parameters
  • Studies on the subjective evaluation of speech and sound quality with people with normal hearing and people hard of hearing from all age groups

Personalized sound quality


Everyone has a personal sound preference and their own perception of loudness. That is why we develop techniques to adjust audio playback to individual hearing requirements, e.g. in smartphones, hearables, consumer electronics, notebooks or in-car infotainment systems. Our solutions are intended both for people with normal hearing and people with hearing impairments.

Sectors and Markets

  • Automotive
  • Hearables, headphones and headsets
  • Telecommunication and telephony
  • Consumer electronics
  • Solutions for call centres and service centres
  • Room acoustics

Speech intelligibility


Our software solutions are able to measure, display and optimize speech intelligibility – automatically if needed. An optimal understanding of speech can create significant added value – for example, in the context of railway station announcements, mobile telephony, noisy workplaces or in-car infotainment systems. In media production, an objective evaluation of speech intelligibility can ensure consistently high quality.

Sectors and Markets

  • Broadcasting and media production
  • Streaming and media libraries
  • Telecommunication and consumer electronics
  • Conference systems
  • Infotainment systems (e.g. in cars or aircraft)
  • Hearing aids
  • Security-critical areas
  • Public address systems

Evaluation and User Studies


We conduct hearing tests and model-based analyses in the framework of research projects or on behalf of clients. For this purpose, we have various laboratories and chambers as well as a central test subject database at our disposal in Oldenburg. We have extensive expertise in transposing complex aspects of hearing perception into instrumental parameters, which our clients can use to optimize the sound of their products and systems.


  • Communication acoustics simulator
  • Study lab with home and work environments
  • Audiometric booths
  • Acoustics measurement lab
  • Audio lab
  • Mobile EEG

Products and solutions


In-ear AI

We develop the hearable for the smart industrial workplace.


Press information / 22.8.2019

The simple way to good, personalized sound

Under the name earis®, Humantechnik GmbH markets a TV listening system developed in collaboration with Fraunhofer IDMT in Oldenburg.


Press information / 10.12.2020

Red when mumbling!

By incorporating speech intelligibility technology into its current solution, Steinberg’s Nuendo now uses a traffic light system to indicate how well the spoken word is objectively understood by listeners.


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.


An insight into our research / 6.11.2019

Interview with Dr. Jan Rennies-Hochmuth

That sound preferences differ from person to person is a factor that should not be underestimated when designing multimedia solutions.

R&D-Services and Licencing

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

»Hearing4all« research cluster

Fraunhofer IDMT-HSA is a partner in the »Hearing4all« cluster of excellence.