Provenance & Recording History
The alleged source device, application, transfer method, exports and known processing history establish what characteristics should reasonably be expected.
Audio Authentication & Integrity
Aesonlabs examines questioned audio recordings for technical consistency, possible discontinuities and evidence of processing or modification. The examination considers the recording itself, its file structure and the circumstances under which it is alleged to have been created.
What Is the Recording Claimed to Be?
Audio authentication is not a universal test that labels every file “original” or “edited.” The examination begins with a defined claim: the device or application said to have produced the recording, whether it is represented as continuous, and what alteration or event is being questioned.
Have a recording that requires examination? Submit a Recording
EXAMINATION SCOPE
Authentication Requires Several Sources of Technical Evidence
No individual test is treated as conclusive when other explanations remain technically possible.
Container, Codec & Metadata
File structure, stream information, timestamps, encoding parameters and software identifiers may be compared with the stated method of creation.
Waveform & Spectral Continuity
Questioned regions are examined for abrupt changes in amplitude, frequency content, phase, background energy and other signal characteristics.
Acoustic Environment
Room tone, noise, reverberation, microphone perspective and recurring environmental sounds can provide continuity information beyond spoken content.
Encoding & Recompression
Compression boundaries and changes in encoding behaviour may indicate export or reprocessing, but they must be interpreted in the context of the complete file history.
Timing & Channel Behaviour
Duration, sample timing, channel relationships, synchronization and unexpected interruptions may be relevant to a specific allegation.
QUESTIONED DISCONTINUITIES
A Visible Seam Is a Lead, Not a Verdict
A sudden boundary may be visible across a spectrogram, waveform or both. That observation can help locate a questioned event and direct closer examination, but its meaning depends on how the recording was produced and handled.
Pausing or resuming a recorder, automatic gain control, dropped transmission data, application behaviour, microphone movement, format conversion and ordinary editing can produce different forms of discontinuity. Some may resemble one another when viewed in isolation.
For that reason, a suspected seam is compared with surrounding room tone, waveform behaviour, spectral energy, codec structure, timing and available metadata. The objective is to determine which explanations are technically supported—not to assign a predetermined meaning to one visual feature.
CONTROLLED EXAMINATION
From Submitted File to Documented Opinion
Preserve and Identify
The submitted item is retained unchanged. Its filename, format, size, available metadata and cryptographic hash are recorded where required by the engagement.
Define the Allegation
The claimed origin, continuity, transfer history and questioned timestamps are established before technical interpretation begins.
Inspect File Structure
The container, streams, codec parameters, metadata and indicators of export or recompression are examined against the stated history.
Examine the Signal
Relevant regions are evaluated through controlled listening, waveform inspection, spectral analysis and other measurements appropriate to the question.
Correlate and Report
Observations are considered together, alternative explanations are assessed and conclusions are reported with their limitations.
RESULT LANGUAGE
Findings Are Not Limited to “Authentic” or “Fake”
The strength and wording of an opinion depend on the material supplied and the specific question that can be tested.
A
Consistent with the alleged recording process. The examined characteristics do not conflict with the stated method of creation or continuity.
B
Evidence consistent with modification or reprocessing. Multiple observations may support editing, export, recompression or another departure from the alleged history.
C
A discontinuity with more than one possible explanation. A technical event is present, but the available evidence does not support one exclusive cause.
D
Insufficient information or inconclusive. A derivative copy, missing provenance or limited signal information may prevent a reliable determination.
FILE STRUCTURE & PROVENANCE
The File Can Carry Evidence Beyond What Is Heard
A digital recording normally combines encoded audio with a container or wrapper. Depending on the format and application, the file may retain information about its codec, sample rate, channels, duration, timestamps, encoding library and other structural characteristics.
These details are compared with the recording history supplied for the case. A mismatch may justify further investigation, but metadata alone rarely proves who created a recording or exactly what happened to it.
Messaging applications, cloud services, social platforms, email systems and editing software may rename, strip or rewrite file information. Whenever possible, submit the original device file using a transfer method that does not convert it.
BEST AVAILABLE SOURCE
Original Files Are Strongly Preferred
An MP3 attachment, messaging-app download or social-media copy may still contain useful information, but it can differ substantially from the original recording. Re-encoding may alter spectral characteristics, remove metadata and create new compression boundaries.
If the original device remains available, preserve it and avoid opening the questioned recording in software that may automatically resave, synchronize or modify the file. Do not rename or convert the only available copy.
Documented Work and Technical Reporting
The original submitted material is not overwritten. Working copies, examination notes, relevant screenshots, technical observations and limitations are maintained according to the agreed scope. When required, a report can describe the material received, the allegation examined, the methodology applied and the basis for the resulting opinion.
Court attendance, testimony, preparation for examination or cross-examination, conferences with counsel and other litigation participation are quoted separately. Audio enhancement, transcription, speaker comparison and synthetic-voice analysis are separate services unless specifically included in the engagement.
Audio Authentication FAQ
Can you determine whether an audio recording was edited?
Potentially. The answer depends on the alleged modification, the recording format, the source supplied and whether the relevant technical characteristics survived copying or re-encoding.
Does a visible spectral seam prove that audio was removed or inserted?
No. A seam identifies a discontinuity that requires interpretation. Recorder operation, transmission problems, gain changes, application behaviour and format conversion may also create abrupt boundaries.
Can a downloaded MP3 or messaging-app copy be authenticated?
It may still be examined, but conclusions can be limited because derivative copies often lose metadata and undergo additional encoding. The original device file is preferred.
Can metadata prove who created a recording?
Metadata may support or conflict with a stated history, but it can be missing, rewritten or altered. It is evaluated alongside structural and signal evidence rather than treated as proof by itself.
Is AI-generated voice detection included?
No. An allegation involving synthetic or AI-generated speech requires a separately defined scope, suitable comparison material and an assessment of the limitations of the available methods.
Can the examination be documented for court?
Yes. The required preservation, documentation and reporting scope should be established before work begins. Admissibility remains a legal determination.
QUESTIONED RECORDING?
Submit the Original File and Explain What Is Being Alleged
Include the source device or application, transfer history, questioned timestamp and whether formal reporting may be required.
Open an Audio Case