Skip to content
SPEARTRACEMedia Forensics
[ CAPABILITY 03 / 05 · VOICE EVIDENCE ]

AUDIOFORENSICS.

Audio forensics for recordings that may be edited or synthesised. We examine spectral continuity, background noise and encoding traces, and mark the exact time ranges on the waveform and spectrogram.

[ 01 / Paradigm shift ]

Target vs Reality

Current

Trusting Your Ears

A convincing voice passes a casual listen. Edits and synthetic speech are hard to hear and hard to prove after the fact.

Target

Measured on the Spectrogram

Sensors measure continuity, hum and encoding behaviour, and the report marks the time ranges with the spectral evidence beside them.

[ 02 / Method ]

Built for scrutiny

  1. 01Preserve

    The original recording is hashed and sealed.

  2. 02Decode

    A reference copy is made while codec details are kept.

  3. 03Measure

    Spectral, noise and hum sensors run independently.

  4. 04Mark

    Time ranges are annotated with spectra and notes.

Audio Analysis Chain

Control planeAnalysis plane

  1. 01Decode & Normalise

    PCM · METADATA

    Decodes to a reference representation while preserving the original stream and codec details.

  2. 02Spectral Sensors

    SPECTROGRAM · PHASE

    Examines spectral continuity, band limits and phase behaviour for signs of synthesis or editing.

  3. 03Noise Floor

    CONTINUITY

    Checks that background noise and room response stay consistent through the recording.

  4. 04Network Hum

    ENF · RE-ENCODING

    Looks for electrical-network hum patterns and traces of repeated encoding.

  5. 05Annotated Report

    TIMELINE · SPECTRA

    Marks time ranges of interest on the waveform and spectrogram with supporting measurements.

  6. Control plane / CUSTODY LOG

    Case Ledger

    Links the source recording to every spectrogram and measurement.

[ 03 / Core systems ]

Core sensors

01 / SPECTRAL01 / 04

SPECTRALCONTINUITY

Natural speech has characteristic spectral and phase behaviour. Edits and vocoders can disturb it.

SPECTROGRAM · PHASE · BAND LIMITS

Inspect the signal's structure.

MEASURES
Spectral smoothness, band limits and phase coherence over time.
REPORTS
Time ranges with abrupt or unnatural spectral behaviour.
LIMITS
Telephone and conferencing codecs alter spectra, so reports state the channel assumptions.
02 / NOISE02 / 04

NOISE FLOORCONTINUITY

Rooms and microphones leave a steady background. Splices often interrupt it.

ROOM RESPONSE · BACKGROUND

Listen to what is under the voice.

MEASURES
Background level and character, and changes in room response.
REPORTS
Points where background changes without an acoustic reason.
LIMITS
Real environments change, so the report shows the change and leaves the interpretation to the examiner.
03 / NETWORK HUM03 / 04

ELECTRICALNETWORK

Mains hum can be matched to an expected pattern for the recording time and region.

ENF · TIMELINE

Use physics as a witness.

MEASURES
Hum frequency variation across the recording.
REPORTS
Discontinuities in the hum track that may indicate cuts.
LIMITS
Not every recording captures hum, and in that case the sensor reports no result.
04 / ENCODING04 / 04

RE-ENCODINGTRACES

Repeated compression leaves marks that single-pass recordings do not have.

CODEC · QUANTISATION

Count the passes.

MEASURES
Codec signatures, frame boundaries and quantisation patterns.
REPORTS
Evidence of multiple encodings and segments with different histories.
LIMITS
Messaging apps re-encode by design, so provenance matters when reading the result.
[ 04 / Reference patterns ]

Where it applies

INVESTIGATION

Disputed recorded call

Time-marked findings that can be played back against the spectrogram.

FINANCIAL

Voice-authenticated transactions

Screening for replayed or synthetic voices on high-risk calls.

COMPLIANCE

Recorded instructions

Checks that archived recordings were not edited after the fact.

[ 05 / Delivery & deployment ]

From evidence to report

Reports carry annotated waveforms and spectrograms, plus the sensor settings. Audio never leaves your environment.

See the analysis demo Deployment and security Request a briefing
[ 06 / Questions ]

Common questions

What does SpearTrace do for audio forensics?

Audio forensics for recordings that may be edited or synthesised. We examine spectral continuity, background noise and encoding traces, and mark the exact time ranges on the waveform and spectrogram.

What changes compared with the current approach?

A convincing voice passes a casual listen. Edits and synthetic speech are hard to hear and hard to prove after the fact. Sensors measure continuity, hum and encoding behaviour, and the report marks the time ranges with the spectral evidence beside them.

Can it run on-premise or air-gapped?

Yes. Analysis runs on your own hardware, and the platform can be installed with no connectivity. Reports are exported as signed PDF and machine-readable JSON.

How do I start?

Request a briefing by form, WhatsApp (+60 17-773 7302) or email (kumar@spearcompute.com). We scope a pilot on samples you provide.

  1. 01 VIDEO FORENSICS
  2. 02 IMAGE FORENSICS
  3. 03 AUDIO FORENSICS
  4. 04 DOCUMENTS & TEXT
  5. 05 AIR-GAPPED PLATFORM
  6. 06 LAW ENFORCEMENT
  7. 07 BANKING & FINANCE
  8. 08 INSURANCE
  9. 09 TELECOM
  10. 10 NEWS & MEDIA
  11. 11 LEGAL & COURTS
  12. 12 GOVERNMENT & ELECTIONS
  13. 13 ENTERPRISE SECURITY
  14. 14 E-COMMERCE & MARKETPLACES
Next capabilityDocuments & Text

Bring the footage.Let’s verify.

Tell us what media you need to trust and where it has to be analysed. We will scope a briefing or a pilot on your own samples.

Request a briefing
WhatsApp Email