SpeechTrust+ – Detection of AI-based speech synthesis and voice alienation for evidence verification and protection against fraud and disinformation

Recording studio with microphone
© Will Francis/Unsplash

AI-based speech synthesis will soon be able to generate speech of such good quality that it will be indistinguishable from natural speech - a form of so-called “deepfakes”. In the near future, it will be possible to put arbitrary messages into the mouth of any person. Effective synthetic speech detection procedures are therefore of great importance to ensure the prevention and prosecution of fraud, phishing and disinformation in the future as well.

SpeechTrust+ aims to explore a new generation of detectors that will reliably and sustainably detect AI-based speech synthesis and voice distortion. To achieve this, we will not only apply the same AI methods that have led to the tremendous improvements in speech synthesis, but also use methods from the field of audio forensics. This combination is meant to create a toolbox for the robust detection of both  speech synthesis and voice distortion.

Responsibilities of Fraunhofer IDMT

Fraunhofer IDMT leads the project and carries out all work related to the research and development of novel AI-based technologies for the detection of synthetic speech and voice distortion. Several Fraunhofer IDMT teams in Ilmenau and Oldenburg contribute to the project with their interdisciplinary know-how in the fields of machine learning, audio forensics, anomaly detection, room acoustics, speaker recognition, and speech analysis. To achieve this, findings and methods from the REWIND and AudioTrust+ projects will be used, among others. 


  • Fraunhofer Institute for Digital Media Technology IDMT
  • DigiFors GmbH
  • State Criminal Police Office of Baden-Württemberg 
  • State Criminal Police Office of Bavaria

DigiFors GmbH, a highly specialized company for forensics analysis and consulting in juridical trials, contributes to the project with its expertise in digital forensics and IT security, especially with regard to the needs from the perspective of the forensic processing of analysis results and the evaluation of the project results.

The State Criminal Police Offices of Baden-Württemberg and Bavaria are involved as associated project partners for requirements analysis and evaluation of the developed software. Their involvement in both processes ensures the practical usability of the detectors, especially regarding the prevention and detection of crimes.


January 2022 – December 2024


The project is funded by the German Federal Ministry of Education and Research as part of the "Research for Civil Security" programme.