© Fraunhofer IDMT/Daniel Schmidt

Understanding more easily

Scientists at Fraunhofer IDMT develop software solutions which automatically analyse and optimise the intelligibility of speech – for applications ranging from railway station announcements and mobile phone calls through to car navigation systems.

Enhancement of Speech Intelligibility

Technical transmission of speech is often subject to superposed interference noise and reverberation, e.g. in the case of railway station announcements or when using mobile phones. The Oldenburg Branch for Hearing, Speech and Audio Technology HSA offers real-time signal processing methods that analyse and represent speech intelligibility under conditions with unknown and variable interference noise. For this purpose, the current acoustic situation is detected using a microphone. An adaptive signal processing algorithm developed at the Fraunhofer IDMT is then able to automatically adapt the speech signal to the background noise. By taking into account the latest hearing research findings, this makes it possible to achieve a high level of hearing comfort even for signals with limited bandwidth and for people with impaired hearing.

Range of Services

  • Software solution SI-LIVE for real-time representation of speech intelligibility
  • Software solution ADAPT DRC for optimisation of speech intelligibility in conditions with interference noise (near-end listening enhancement)
  • Development and application-specific adaptation of signal processing methods
  • Evaluation studies

Products and Solutions



Real-time monitoring of speech intelligibility


Press Release / 10.12.2020

Red when mumbling!

Intelligibility Meter enables objective measurement and display of speech intelligibility in media productions



Real-time optimization of speech intelligibility

Current Research


Better speech intelligibility in TV broadcasts

Research project SI4B