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Audio Forensics

We have worked with attorneys, law enforcement agencies, government agencies and private individuals on a variety of audio cases.  As a result, we have worked with hundreds of the best trial lawyers in the world.

An Audio Forensic expert applies a scientific approach to recovering, evaluating, enhancing, clarifying, and/or authenticating recordings to be used in court. The primary aspect of audio forensics is establishing the authenticity of audio evidence. This is especially important; often times audio recordings in criminal and civil litigation are presented by police or the opposing attorneys and may be miss interpreted. Once authenticity of the audio evidence is established, the forensic expert must rely on other techniques as well as their own expertise to determine the authenticity of the chain of custody, such as requesting the original.

Best Practice is That We Analyze the Original Evidence

If the original recording is on analog media, playback and duplication rely on physical processes that introduce noise and degrade the signal, even if slightly. A copy of an analog recording can never be an exact duplicate. An original digital recording is a bit stream from which the acoustic audio signal can be generated. Exact copies of that bit stream can be made. With digital evidence, each stage of copying can be exact, with no loss of quality between generations.

ANALYSIS

Enhancement/Clarification

One of the most common audio issues that we address during an enhancement is noise and other extraneous “unwanted” sounds. The noise floor is usually consistent throughout the recording. That means it can be removed to varying degrees by using noise reduction software. The most complicated issues are the extraneous sounds that are not continuous. These sounds could include anything from a plane flying overhead to someone whistling while people talk. These sounds are difficult to pinpoint with standard tools such as noise reduction and equalization, but they can be identified using a spectrogram. After critical listening, the forensic expert must use electronic measurement to examine the audio evidence.

Visual Inspection

Audio Editing Software

Analyzing Metadata in Digital Audio Evidence

Shows form with Metadata info

Digital audio recordings contain metadata which reveals information about how the recording was made. The metadata also determines the type of equipment that created the recording. If a recording was loaded into a software program capable of performing edits, there will often be a footprint left in the recording.

We can examine and analyze a variety of audio recordings, including but not limited to:

  • Phone calls
  • iPhone recordings
  • 911 Dispatch
  • Law Enforcement Dash Camera
  • Law Enforcement Wire Tap
  • Concealed Audio Recorders
  • Confidential Informant
  • CCTV Surveillance Audio
  • Voice Mail (butt dial)

If you have a video that you question or need help understanding, please give us a call (312) 818-4788. Any and all formats of audio and video accepted. Retainer agreement available on request; travel expenses will be quoted in advance excluding meal expenses and flat rate time for travel instead of hourly.