February 28, 2017

“OT-Contact” participated in international scientific-practical conference “Special forensic technology” with a report on “Special software applications for forensic video and audio analysis”. “OT-Contact” represented new capabilities and functionality of "ÎÒExpert", "HEX-Expert", "DB-Expert" and "DTP-Expert".

November 02, 2016

OT-Contact” provided a presentation of new functionality of software application complex “DTP-Expert” for government forensic experts.

September 29, 2015

«DTP-Expert» received approval from Ministry of Justice Scientific Council for usage in forensic video examination laboratories.

Professional forensic audio investigation system «OTExpert»


Software register certificate #2008615280 01 November 2008

«OTExpert» software application is designed for the purposes of automation of forensic audio examination research. The system contains full set of tools and methods for all audio forensic tasks solved by the expert: forensic audio decoding, speech processing and preliminary analysis including preprocessing, speech intelligibility improvement, sound to noises level evaluation, forensic audio authenticity verification and forensic speaker voice identification.

The system is approved by scientific council of Russian Ministry of Justice Forensic Examination Centre.

The system contains several modules and can be configured according to particular list of forensic tasks solved in the forensic division.

ID-Expert is a general software shell, containing basic functionality for audio signal analysis and additional tools and methods for forensic audio decoding, speech preliminary analysis and forensic speaker voice identification. Special instruments designed for modern methods of audio investigation and speech signal analysis are implemented to be convenient and intuitive.

Basic functionality:

  • all audio file formats supported;
  • advanced visualization representation: waveform, FFT and LPC dynamic spectrograms, cepstrogram and energy. Double and Triple signal windows allows to analyze same file or two or three different files in a separate software window;
  • advanced playback options: loop, consequent playback for phonetic comparison, independent stereo;
  • wide set of preprocessing tools: broad/narrow band filtering, inverse/target filtering, filtering by sample, spectral subtraction;
  • comparison of audio segments spectra;
  • useful signal to noises level ratio calculation;
  • automatic extraction and manual editing of pitch and formants tracks over cepstrogram/spectrogram;
  • statistical analysis of pitch and formant data;
  • signal generator;
  • easy export options of charts, text and images.

Audio decoding tools provide text and speech synchronization for search of matching words in two audio signals automation. Wide functionality of user marks allow to collect speaker phonetic profile and to find matching phoneme/articulations in two speech signals.

TD-Expert – module is designed for forensic audio authenticity analysis, detection of editing and audio manipulation traces, signal and signal properties continuity breaks, traces of previous coding by psychoacoustic codecs. Modern and scientifically based method of psychoacoustic codec traces extraction over signal properties without using information from file header (which is analyzed by means of HEXExpert module).

Module functionality:

  • delicate and precise audio signal resampling;
  • extraction and continuity analysis of narrowband background harmonics phase;
  • calculation and analysis of samples histograms;
  • samples distribution centre behavior graph calculation;
  • levelogram tool for signal compression and amplification detection;
  • matching fragments search – detection of copy/paste inside same or two different files;
  • automatic search for repeating samples sequences;
  • detection of audio codecs previously used to store the signal:
    • MPEG-1/2/2.5 Layer 3 (MP3);
    • Advanced Audio Coding (AAC);
    • Windows Media Audio (WMA);
    • Vorbis used within OGG container;
  • codec frames order and periodicity analysis.

HEX-Expert is designed for audio and video file structure and file header analysis. Additional module FAT-Expert allows to conduct the research of media data storage to prove the original file was recorded by the device and have not been manipulated.

ENF-Expert is the module dedicated to analysis of power supply (Electric Network Frequency) pickups, appearing in every forth real case examination.

Module functionality:

  • automatic extraction of power supply pickups;
  • automatic search for ENF pattern from audio recording in ENF database;
  • ENF-Server – Special hardware system for collection of ENF database;
  • automatic date and time labeling of audio according to ENF database.