Authentication of Recordings
Authenticity examinations of audio and video recordings are normally conducted on the alleged original media, and can usually determine whether the information is original, continuous, and unaltered.
The examination consists of, as appropriate, aural, physical, visual, magnetic, instrumental, metadata, and computational analyses, which can identify alterations, discontinuities, and duplication processes.
Enhancement examinations of audio information are normally conducted on the original media, and can often attenuate reverberation, tonal sounds, noise outside the frequency range of the voice material, and certain types of environmental and system noise; level the amplitude differences between louder and quieter voices; and correct speed errors.
This analysis uses specialized forensic digital filters, gain-reduction devices, dedicated software, and unique playback systems, as appropriate.
Conversion of Unique & Specialized Audio Formats
Many unique and specialized audio formats are able to be converted to standard formats readily usable by the client. Submitted formats often include miniature, professional, unique on-the-body systems, antiquated, and proprietary digital formats, such as those used in 911 dispatch recordings.
Identification & Classification of Non-Voice Signals
Examinations of non-voice signals, conducted with original media, include electronic signal analyses of recorded gunshot sounds, telephone signaling, mechanical sounds associated with weapons firing, room acoustics, and various background noises.
Additional Audio Forensic Services
Repair of Damaged Media
Redaction of Designated Information from Recordings
Preparation of Video / Audio Sequences
Preparation of Transcriptions
Broken or damaged tapes, housings, and other components can often be repaired, which will allow proper playback and duplication.
This examination allows for specific talkers or certain phraseology to be removed or isolated. This procedure is often requested based on a legal decision that certain recorded statements cannot be played to the jury, or when only certain designated voices in a conversation are pertinent.
These procedures produce professional-quality video and/or audio clips of interest in a designated display sequence. Effects can include transitions, looping, slow motion, zoom, magnification, and titling.
While typically considered a non-expert area, transcriptions are normally prepared using the original media, and state-of-the-art playback and enhancement equipment, and by careful, repeated review of the recorded speech information using professional-quality headphones.
BEK TEK LLC Offers
Technical Support & Training
Instruct attorneys, investigators, laboratories, examiners, and others regarding the scientific basis and methodology of forensic examinations of audio and video recordings; this can either be an individual consultation, or in a formal classroom environment. BEK TEK LLC personnel can also technically evaluate appropriate recording and analysis equipment.
BEK TEK LLC personnel can either provide technical assistance or conduct appropriate research in support of forensic areas, such as authenticity, enhancement, and signal analysis.
On-site evaluations of acoustical sounds and environments require BEK TEK LLC personnel to travel to the designated locations, perform appropriate acoustical testing, analyze the collected information in the laboratory, and then draw conclusions regarding the collected material. Examples of these analyses include on-site testing of the audibility of speech in different locations in a building, and evaluations of equipment that cannot be removed from its present location.
Expert Testimony Support
Provide expert testimony regarding laboratory examinations and on-site evaluations conducted by BEK TEK LLC personnel, and assist attorneys in cross-examination of lay witnesses and opposing experts regarding their prior testimony, the scientific validity of their findings, their background and experience, and the methodology of their laboratory work.