OTExpert review

Short video introduction >>

OTExpert is a powerful Forensic Audio Examination Set that provides audio expert wide spectrum of solutions and reflects the contemporary demands of voice identification and authenticity analysis methods.

In 2003 software application complex OTExpert was tested by Scientific Council of Russian Ministry of Justice Forensic Examination Center and then recommended for usage in all Ministry forensic audio labs.

As the producer is highly interested in feedback and the program code is conducted on the contemporary state-of-art basis the wide distribution of OTExpert brought a lot of enhancements and new functions due to professional users demands. Accessibility of the system architecture and high interface usability provide fast and accurate approach to the signal and speech analysis.

Wide spectrum of functions consists of six major blocks:

Recording and playback. All audio formats and digital settings are supported, input/output level control, clipping notification. Simple editing functions. Loop playback, consequent playback of chosen fragments from two different files, pseudo stereo mode, tempo correction.

Visualization. Oscillogram, spectrogram, LPC-spectrogram, and cepstrogram representation of the signal. Fast switch between modes. Additional information shown over main layer (energy, pitch, formants, user marks and notes). Fast signal navigation. Two clicks to the function settings (frame type and size, spectrum normalization). Fast calculations and information management. Signals synchronization. Rich color presets pallet. Full image export with user presets.

Automatic speaker characteristics extraction. Pitch and formant traces extractor, manual correction options via visual control. Calculation, comparison, and storing of pitch and formants statistics. MS Word export.

Text editor. Color highlighting of speakers utterances. Convenient speech segmentation. Text-to-audio binding and fast text navigation. Automatic search of matching words and phrases for further comparison analysis.

Editing. High-pass, low-pass, band-pass, inverse filtering. FIR, IIR filtering. Easy settings access.

Authenticity analysis. Samples distribution analysis. Technical harmonics phase continuity investigation. Files header analysis.

Rich and precise functional environment of interrelated procedures implemented via user-friendly interface provide fast and comfortable speech and audio analysis on the high professional level.

Here are some examples of exported images:

Segmentation of the recording and textual transcribing.


Pic. 1. Pitch distributions comparison.

Black regions on dynamic cepstrograms (frequencies vertical axis, time - horizontal) reflect the behavior of speakers pitch:


Pic. 2. Comparison of prosodic constructions, used by speaker in two recordings.

Pic. 3. Comparison of prosodic constructions, used by speaker in two recordings.

Spectra of consonants can also match:

Authenticity analysis.

Brakes of harmonics phase:

Pic. 13. Small brakes and smoothed changing of power-supply (50Hz) harmonics phase.

Pic. 14. Brakes of 76.56Hz harmonics phase.

Pic. 15. Insertion of 16-bit interval into A-law compressed file.