TRM vs. WAV for Court Recordings: Format Comparison for Legal Professionals
TRM files preserve multi-channel court audio with metadata. WAV files are universal but lose channel data. Compare formats and learn which to request from your court.
When you request a court recording, you may be offered a choice of file formats — or you may get whatever the court provides without being asked. In most courtrooms using digital recording systems, the two formats you're most likely to encounter are .TRM (from ForTheRecord systems) and .WAV (the universal uncompressed audio standard).
The format you receive affects what you can do with the recording, how easily it can be transcribed, and how much useful information survives the journey from courtroom microphone to your desk. Understanding the differences helps you make a smarter request and avoid unnecessary headaches downstream.
Understanding Court Audio File Formats
Courts record proceedings using digital audio systems that capture sound from multiple microphones positioned throughout the courtroom. The judge's bench, attorney tables, witness stand, jury box, and courtroom gallery may each have dedicated microphones feeding into the recording system.
How the system stores those audio streams — and how much information it preserves — depends on the file format. The two most common formats in the legal context serve fundamentally different purposes.
TRM is a proprietary format created by ForTheRecord (FTR), the court recording platform used in thousands of courtrooms across the United States, Canada, Australia, and the United Kingdom. TRM is designed specifically for court recording and optimized for the unique requirements of legal audio.
WAV (Waveform Audio File Format) is a universal, uncompressed audio standard that has been around since 1991. It's supported by virtually every audio player, editor, and transcription service on the market. Courts that don't use FTR systems, or courts that offer export options, often provide recordings in WAV format.
What TRM Files Contain (and WAV Files Don't)
The most important difference between TRM and WAV isn't audio quality — it's information density. TRM files carry significantly more data than WAV files from the same recording session.
Multi-Channel Audio
ForTheRecord systems record each courtroom microphone as a separate audio channel within a single TRM file. A typical TRM recording might contain 4 to 16 individual channels — one for the judge's bench mic, one for each attorney table, one for the witness stand, one or more for the gallery, and ambient room audio.
This channel separation is powerful for transcription. When a transcription service (or a listener) needs to isolate what a specific speaker said, they can turn up the channel for that speaker's microphone and turn down everything else. This makes it dramatically easier to understand overlapping speech, filter out background noise, and accurately attribute statements to specific speakers.
WAV files, by contrast, are typically delivered as a stereo (2-channel) or mono (1-channel) mixdown. All the courtroom microphones are blended into a single audio stream. Once that mixdown happens, the ability to isolate individual speakers is lost. You hear everyone at once, at whatever relative volume the court's mixing system assigned.
Session Metadata
TRM files embed metadata within the file itself: case numbers, court identifiers, recording session start and end times, date stamps, and channel labels indicating which microphone is assigned to which channel. This metadata makes it possible for software to automatically organize and label the recording.
WAV files contain minimal metadata — typically just the sample rate, bit depth, and number of channels. There's no built-in mechanism for case identification, session labeling, or channel assignment. Any organizational context must be tracked separately through file naming conventions or external documentation.
File Size
TRM files use compression that significantly reduces file size compared to raw uncompressed audio. A full day of multi-channel court recording might produce a TRM file in the range of 500 MB to 2 GB, depending on the number of channels and session length.
The same recording exported as a multi-channel WAV file could easily reach 5 to 15 GB, because WAV stores uncompressed audio data. Even a stereo WAV mixdown of a full-day session will typically be several gigabytes.
For attorneys and paralegals who need to download, store, and transmit court recordings, this size difference matters. Large WAV files take longer to download, consume more storage, and may exceed email attachment limits or upload caps on transcription services.
When WAV Is the Right Choice
Despite TRM's advantages, WAV is the better choice in several common scenarios.
When you need to share the recording with someone who doesn't have TRM-compatible tools. WAV is universally playable. Any attorney, expert witness, client, or co-counsel can open a WAV file on any computer or phone without installing special software. TRM files require FTR Player or a TRM-compatible service, which creates friction when sharing.
When you're using a transcription service that doesn't accept TRM. Most transcription services — both human and AI — accept WAV files but reject TRM files. If your transcription provider can't handle TRM, you'll need WAV (or MP3, which most services also accept).
When the court doesn't use ForTheRecord. Not all courts use FTR systems. Courts that use other digital recording platforms, or courts that offer audio exports through their case management systems, typically provide WAV or MP3 files. In these cases, the choice is made for you.
When you need to edit the audio. Audio editing software like Audacity, Adobe Audition, and similar tools work natively with WAV files. If you need to clip a segment, enhance audio quality, or prepare an exhibit, WAV is the more practical format.
When TRM Is the Right Choice
TRM is the better choice when your workflow can take advantage of its additional capabilities.
When you're using a transcription service with native TRM support. If your transcription service reads TRM files directly, you preserve all the multi-channel and metadata advantages without any conversion step. MatterScribe is the only independent AI transcription service with native TRM support — upload the file directly without any conversion step.
When you need the best possible speaker identification. The multi-channel audio in TRM files gives transcription software (and human transcriptionists) a significant advantage in determining who said what. If your proceeding involved overlapping speakers, sidebar conversations, or multiple attorneys, TRM's channel separation produces more accurate speaker labels.
When you want to preserve the complete recording. TRM files are the native output of the court's recording system. They represent the most complete version of what was captured. Once audio is exported to WAV, any channel separation or metadata that didn't survive the export is gone permanently.
When storage efficiency matters. If you're archiving recordings from many proceedings, TRM's compression means you can store roughly 5 to 10 times more audio in the same disk space compared to WAV.
How to Work With Both Formats
In practice, many attorneys end up working with both formats at different points in a case. Here's a practical framework.
Request TRM from the court when available. It preserves the most information and gives you the most flexibility. You can always convert TRM to WAV later, but you can't go the other direction — once multi-channel audio is mixed down to a WAV file, the channel separation is permanently lost.
Use TRM directly for transcription if your service supports it. MatterScribe handles TRM files natively, so there's no reason to convert. If you're using a service that requires WAV, you'll need to export through FTR Player first.
Convert to WAV or MP3 for sharing. When you need to send the recording to co-counsel, a client, or an expert witness, export a WAV or MP3 version so they can play it without special software.
Keep the original TRM file. Even after converting or transcribing, retain the original TRM as your authoritative source. If a question arises later about what was said, the multi-channel TRM is your best evidence.
Requesting Recordings From Courts: Format Tips
When requesting a recording from a court clerk, a few practical tips can save you time and frustration.
Ask what format is available. Some courts offer both TRM and WAV exports. Others provide only TRM (or only WAV, if they don't use FTR). Knowing in advance what you'll receive lets you plan your transcription workflow.
Specify electronic delivery if possible. Many courts can now deliver recordings electronically — via email, download link, or secure portal — rather than requiring you to pick up a physical CD or USB drive. Electronic delivery saves days of turnaround time.
Note the channel assignments. When you receive a TRM file, ask the clerk (or check any accompanying documentation) for the channel map — which channel number corresponds to which microphone location. This information helps your transcription service produce more accurate speaker labels.
Be aware of retention policies. Courts have varying retention periods for audio recordings. Some courts delete recordings after 30 to 90 days unless a transcript has been ordered or the recording has been specifically preserved. Don't assume the recording will be available indefinitely — request your copy promptly.
Check file sizes before downloading. Multi-channel WAV exports can be very large (10+ GB for a full-day session). Make sure your download connection and storage can handle the file before you start.
The Bottom Line
TRM files preserve more information from the courtroom recording — multi-channel audio, session metadata, and channel assignments — in a smaller file. WAV files are universally compatible and easier to share, but lose the multi-channel separation that makes speaker identification more accurate.
For transcription specifically, TRM is the superior format when your transcription service supports it natively. MatterScribe reads TRM files natively, preserving the multi-channel audio and metadata that would be lost in a conversion to WAV or MP3.
The practical advice: request TRM when you can, keep it as your master copy, and convert to WAV only when you need universal compatibility.
Ready to transcribe your court recordings? MatterScribe handles both TRM and WAV natively. Start your free 14-day trial.
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