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Model infoModelsSnapshot: 15 Oct 2026

Modulate / Velma-2

Deepfake Detection

Synthetic-voice classification of single-speaker audio, returning timed verdicts and confidence rather than proof of speaker identity.

availableClosed weightsDeepfake detection
Official documentation (opens in a new tab)Reviewed 13 Oct 2026
9 of 20 specification fields collected
Direct file limit100 MB per prerecorded uploadSee specification notes below
Analysis outputClassification metadataSee specification notes below
Input billingSee ratesModulate Models API · batch
Output billingSee ratesPublished units and conditions below

Specifications

Provider-documented facts. “Not collected” means we have not verified that field yet, not that the feature is unsupported.

Context / input limit
Not collected
Maximum output
Not collected
Output modalities
Classification metadataSource for Output modalities (opens in a new tab)
Reasoning
Not collected
Tool calling
Not collected
Structured output
Not collected

Fixed response JSON fields are documented. No caller-supplied constrained generation schema has been verified.

Batch processing
SupportedSource for Batch processing (opens in a new tab)

Synchronous file-processing endpoint; this does not imply asynchronous multi-file jobs or a discounted text batch API.

Fine-tuning
Not collected
Knowledge cutoff
Not collected
Release date
Not collected
Parameters
316 million parametersSource for Parameters (opens in a new tab)

Provider-reported detector size. Not assigned to the whole Velma ensemble or any other model.

Architecture
Not collected
Languages
Not collected
Context caching
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Maximum audio file
100 MB per prerecorded uploadSource for Maximum audio file (opens in a new tab)
Billing conditions
Per audio hour, with separate batch/live rates where published; see endpoint rates for optional enrichment chargesSource for Billing conditions (opens in a new tab)
Classification labels
synthetic, non-synthetic, no-contentSource for Classification labels (opens in a new tab)
Model aliases
Legacy Speech DF Arena submission name: VELMA-2Source for Model aliases (opens in a new tab)

This benchmark alias is specifically the deepfake detector, not a benchmark of every Velma product.

Access & pricing

Prices belong to an endpoint and billing tier. A provider listing does not guarantee access for every account or region.

Modulate Models API · batch

Provider source (opens in a new tab)
API model ID
/api/velma-2-synthetic-voice-detection-batch

Endpoint path selects the served family; not a request model parameter or immutable checkpoint ID.

Access
POST https://platform.modulate.ai/api/velma-2-synthetic-voice-detection-batch with X-API-Key and multipart upload_file. Response is synchronous.
Regions
Public endpoint deployment region and regional routing are not specified in the reviewed API contract.
Output modalities
Classification metadataSource for Output modalities (opens in a new tab)
Concurrent requests
Authentication guide default: 3 in-flight requests/connections per model; organization-specific limits may differSource for Concurrent requests (opens in a new tab)

Pricing lists 5 for some detectors. Confirm the applicable organization quota; English diarized streaming may have a lower ceiling than plain transcription.

Maximum audio file
100 MB per prerecorded uploadSource for Maximum audio file (opens in a new tab)
API request fields
upload_fileSource for API request fields (opens in a new tab)

Only fields present in this endpoint’s reviewed request schema. A provider marketing option is not automatically a valid form field.

Audio formats
View all 96 entries
  • 3g2
  • 3ga
  • 3gp
  • 3gpp
  • 8svx
  • aa3
  • aac
  • ac3
  • act
  • adts
  • aif
  • aifc
  • aiff
  • alac
  • amb
  • amr
  • ape
  • asf
  • at3
  • au
  • avi
  • avr
  • awb
  • bwf
  • c2
  • caf
  • dss
  • dts
  • dtshd
  • eac3
  • ec3
  • f4a
  • f4b
  • flac
  • flv
  • gsm
  • iff
  • m2a
  • m2ts
  • m4a
  • m4b
  • m4r
  • m4v
  • mka
  • mkv
  • mlp
  • mmf
  • mov
  • mp+
  • mp1
  • mp2
  • mp3
  • mp4
  • mpa
  • mpc
  • mpeg
  • mpg
  • mpga
  • mpp
  • mts
  • mxf
  • nist
  • oga
  • ogg
  • ogx
  • oma
  • omg
  • opus
  • paf
  • pvf
  • qcp
  • ra
  • rf64
  • rka
  • rm
  • rmvb
  • sf
  • shn
  • snd
  • sph
  • svx
  • tak
  • thd
  • ts
  • tta
  • vob
  • voc
  • vqf
  • w64
  • wav
  • wave
  • weba
  • webm
  • wma
  • wmv
  • wv
Source for Audio formats (opens in a new tab)

Container acceptance implies processing its audio track, not video understanding.

Prices retain their published currencies and billing units below.

Published billing units · original currency · observed 13 Oct 2026
CategoryUsageRateUnit
Audio analysisBatch Deepfake Detection1$0.25audio hour

Rate conditions

  1. Published self-service hourly audio rate, credit-based billing; taxes and negotiated enterprise terms are separate. Optional feature surcharges, where applicable, require the provider’s current account conditions. No text-token rate or cost per question is inferred.
Pricing source (opens in a new tab)

Data & enterprise terms

Terms: standard API content and outputs are not retained unless storage is enabled or required by the feature; stored content defaults to 35 days, with separately retained usage metadata and temporary residual backup/log copies. Self-service accounts are automatically enrolled in model improvement. FAQ narrows training to audio marked for storage; enterprise participation and opt-out depend on the agreement. Accent documents a per-request training_permitted=false opt-out. Do not infer a universal no-training or immediate-deletion guarantee.

Read the service policy (opens in a new tab)

Modulate Models API · streaming

Provider source (opens in a new tab)
API model ID
/api/velma-2-synthetic-voice-detection-streaming

Endpoint path selects the served family; not a request model parameter or immutable checkpoint ID.

Access
Connect to wss://platform.modulate.ai/api/velma-2-synthetic-voice-detection-streaming with api_key in the WebSocket query. Send the endpoint-specific audio/config frames and finish with its documented end-of-stream signal.
Regions
Public endpoint deployment region and regional routing are not specified in the reviewed API contract.
Output modalities
Classification metadataSource for Output modalities (opens in a new tab)
Concurrent requests
Authentication guide default: 3 in-flight requests/connections per model; organization-specific limits may differSource for Concurrent requests (opens in a new tab)

Pricing lists 5 for some detectors. Confirm the applicable organization quota; English diarized streaming may have a lower ceiling than plain transcription.

Audio sample rates
8,000 Hz, 11,025 Hz, 16,000 Hz, 22,050 Hz, 32,000 Hz, 44,100 Hz, 48,000 Hz, 96,000 HzSource for Audio sample rates (opens in a new tab)

Accepted raw transport rates; not separate model variants or a claimed native model sample rate.

Audio channels
1–8 input channels for raw audioSource for Audio channels (opens in a new tab)

Input channel count does not establish multichannel speaker identity preservation.

Audio formats
Compressed containers and raw PCM/μ-law/A-law; use the exact audio_format enum in this endpoint’s documentationSource for Audio formats (opens in a new tab)

Raw formats require sample_rate and num_channels; supported formats and first-frame rules vary by endpoint.

Output formats
JSON WebSocket eventsSource for Output formats (opens in a new tab)

Prices retain their published currencies and billing units below.

Published billing units · original currency · observed 13 Oct 2026
CategoryUsageRateUnit
Audio analysisStreaming Deepfake Detection1$0.25audio hour

Rate conditions

  1. Published self-service hourly audio rate, credit-based billing; taxes and negotiated enterprise terms are separate. Optional feature surcharges, where applicable, require the provider’s current account conditions. No text-token rate or cost per question is inferred.
Pricing source (opens in a new tab)

Data & enterprise terms

Terms: standard API content and outputs are not retained unless storage is enabled or required by the feature; stored content defaults to 35 days, with separately retained usage metadata and temporary residual backup/log copies. Self-service accounts are automatically enrolled in model improvement. FAQ narrows training to audio marked for storage; enterprise participation and opt-out depend on the agreement. Accent documents a per-request training_permitted=false opt-out. Do not infer a universal no-training or immediate-deletion guarantee.

Read the service policy (opens in a new tab)

Caching

Caching can reuse earlier input processing. Availability, lifetime and billing depend on the endpoint. A cache hit still generates a new response.

01 / INITIAL INPUTProcess & retain

The system processes eligible input and retains reusable state.

02 / LATER REQUESTCheck available state

Reuse depends on matching input, session state and the cache policy.

03 / CACHE HITReuse & generate

Reusing state can reduce repeated work. Any charges follow the billing rules below.

Modulate Models API · batch

/api/velma-2-synthetic-voice-detection-batch
Not verified

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

How it works
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Minimum reusable input
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Lifetime & refresh
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

How to enable it
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Usage fields
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Billing rules
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Limits & data boundaries
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

No verified cache rate for this endpoint. An empty rate is not a zero charge.

Modulate Models API · streaming

/api/velma-2-synthetic-voice-detection-streaming
Not verified

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

How it works
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Minimum reusable input
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Lifetime & refresh
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

How to enable it
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Usage fields
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Billing rules
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

Limits & data boundaries
Not collected

No discounted prompt-cache or persistent model-cache contract verified for these audio endpoints. Streaming buffers, stored clips and per-session speaker labels are not prompt caching.

No verified cache rate for this endpoint. An empty rate is not a zero charge.

What the measurements say

Speech DF Arena · average EER (provider snapshot)

Modulate · provider-reported
1.104% EER

Provider’s August 19, 2026 snapshot across 14 datasets, legacy VELMA-2 entry. Not independently remeasured here. Lower is better. EER is threshold-dependent and does not establish production accuracy, current rank, streaming latency or performance in all languages.

Evaluation source (opens in a new tab)

Speech DF Arena · pooled EER (provider snapshot)

Modulate · provider-reported
1.1% EER

Provider’s August 19, 2026 snapshot across 14 datasets, legacy VELMA-2 entry. Not independently remeasured here. Lower is better. EER is threshold-dependent and does not establish production accuracy, current rank, streaming latency or performance in all languages.

Evaluation source (opens in a new tab)

Latency and throughput depend on the host, request size, reasoning settings and load. There is no measured speed or global usage figure in this record.

The record behind the model

Why it is included

Modulate presents these as its Velma model suite and audio-native proprietary technology. Its terms retain rights in algorithms and models and license hosted inference, with no public weight artifact identified. Entries represent the named closed managed model families, including ensembles, not invented individual internal checkpoints.

Classification evidence (opens in a new tab)

Sources reviewed