By Bridget McGillivray
Last Updated
Speech-to-text on premise deployment means your audio stays fully inside controlled infrastructure, from locked-down VPC containers to GPU racks in secured datacenters. Under frameworks such as GDPR, voice recordings are classified as personal data, creating legal and financial consequences when data travels outside approved boundaries.
Two vendors can claim identical specs, including “HIPAA compliant,” “enterprise ready,” and “sub-300ms latency,” yet behave differently under real traffic. One may fail during call surges, while another can sustain 140,000+ concurrent streams without packet loss.
Three real drivers justify the on-premise path: compliance requirements that mandate data residency, latency targets that cloud hops cannot meet, and cost stabilization when workloads exceed predictable thresholds. Large enterprises, including retail pharmacies and financial institutions, adopt on-premise speech-to-text precisely because cloud latency or uncontrolled data movement disrupts critical workflows.
This guide cuts through marketing claims with operational evidence: how to determine when on-premise makes sense, how to evaluate solutions, and how enterprises deploy them in real environments.
When speech-to-text On Premise Makes Sense (And When It Doesn't)
Three forces determine whether speech-to-text on premise is the right match: compliance constraints, latency needs, and cost efficiency. When two of the three favor on-premise deployment, the investment produces measurable ROI.
Compliance: HIPAA and GDPR classify voice as protected data. Auditors expect proof that recordings never cross unmanaged networks. Running engines internally eliminates multi-party BAAs and accelerates security review timelines. Internal reviews often complete in 2–4 months; cloud reviews can extend to 4–8 months. Financial institutions face similar requirements. Trading desks cannot allow audio with sensitive content to traverse external endpoints.
Latency: Cloud hops introduce 150–250 ms before inference begins. Co-locating engines with application servers removes that overhead and maintains sub-300 ms responsiveness. This matters for IVR, live agent assist, and real-time call analytics where every millisecond affects user experience.
Cost: Cloud transcription priced at $0.10–$1.00 per hour scales sharply with volume. At 100,000 hours monthly, that ranges from $96,000 to $144,000. Internal deployments amortize costs across predictable workloads and often break even around the 50,000- to 100,000-hour threshold.
Cloud remains preferable for unpredictable usage, limited internal ops capacity, or flexible prototyping needs.
Open-Source vs. Commercial: The First Decision You'll Make
Your earliest fork determines your engineering investment.
Open-Source (Whisper, Wav2Vec2, Kaldi)
Free model weights mask real costs:
- 3–6 months engineering time before production readiness
- ~0.25–0.5 FTE ongoing maintenance
- GPU provisioning, monitoring, autoscaling, logging built manually
“Free” often exceeds $200K in real-world cost before serving a single user.
Accuracy gaps matter. Whisper achieves 8–14.7% Word Error Rate (WER) on clean benchmarks. In noisy multilingual audio, WER can spike to 25–35%.
Commercial Engines
Higher upfront costs but faster time-to-production:
- Continuous updates
- Uptime guarantees
- Compliance documentation
- Support for downtime and incident response
Deepgram’s Nova-2 reduces error rates by up to 30% compared to Whisper on noisy, accented, multi-speaker audio.
Open-source works when you have engineers dedicated to building infrastructure. Commercial engines work when you need production-readiness now.
Five Factors That Determine On Premise Success
On-premise deployments succeed when five technical and operational dimensions stay aligned.
Production Infrastructure Requirements That Actually Matter
CPU-only nodes deliver acceptable demos but fail under real-time load. Transformer models require NVIDIA GPUs for concurrency and low latency. A single T4 or A10 can handle 50 to 100 active streams while maintaining sub-300 ms performance. CPU-only deployments struggle to process batch workloads efficiently.
Container orchestration ensures reliable uptime. Kubernetes or Podman restart failed workers automatically and scale out in 30 to 60 seconds. Bare-metal, single-node setups create fragility.
Minimum requirements for stable deployments include:
- 16 GB system RAM
- Linux x86-64
- Fast local storage
- One terabyte for tens of thousands of recordings plus logs before archived storage
Accuracy Under Production Load: Benchmarks vs. Reality
Benchmarks do not represent reality. LibriSpeech and CommonVoice consist of clean audio. Real audio contains cross-talk, regional accents, HVAC noise, speaker distance variation, and cheap headsets.
Data points that matter:
- Whisper achieves under 8% WER on LibriSpeech
- Real clinical environments: 25–35 percent WER
- Generic models miss 40 percent plus domain terms
- Streaming accuracy often loses 3–5 percent compared to batch
- Deepgram Nova-2 maintains strong accuracy under noise, accents, and multi-speaker conditions
The only meaningful evaluation is performance on your audio samples.
Deployment Flexibility vs. Vendor Lock-In
Providers often claim on premise readiness but require:
- Proprietary orchestration
- Cloud management consoles
- Hidden API inconsistencies
- Forced SDK layers
- Non-portable formats
A durable solution must run on standard Docker or Kubernetes without dependencies on external infrastructure. The same container image should work in a datacenter, a private VPC, or isolated networks. Audio must remain stored in open, portable formats.
A common enterprise pattern: run sensitive calls internally while using cloud analytics for non-PHI data. That hybrid flow only works when APIs, formats, and containers stay portable.
Total Cost of Ownership
Costs shift rather than disappear:
- $50,000 to $200,000 for GPU servers, networking, and storage
- 15 to 30 percent annual maintenance
- DevOps oversight
- Cooling and power
- Secure archival storage
Cloud usage at 100,000 hours monthly costs $96,000 to $144,000. Internal infrastructure often breaks even within months when volume is stable.
Compliance, Security, and Audit Requirements
Regulations shape architecture more than performance metrics:
- GDPR enforces penalties up to 4 percent of global revenue
- HIPAA requires PHI protection and verifiable access controls
- SOX mandates data integrity
- PCI DSS requires immutable logs
Some industries need:
- Seven-year retention
- Air-gapped environments
- Auditable access trails
- Full network isolation
Questions That Expose Vendor Gaps Before You Sign
Asking the right questions upfront prevents painful rebuilds later. Each question aligns with one of the five factors above. After you ask the question, the real value is knowing how to interpret the answer.
1. Accuracy under load
Ask: “Show accuracy with 1,000 plus concurrent streams and noisy, accented, cross-talk audio.”
Interpretation: If they rely on LibriSpeech numbers, they lack production realism.
2. Infrastructure transparency
Ask: “Exactly how many streams per GPU? Which cards? What happens at capacity limits?” Interpretation: Clear answers suggest tested, documented performance. Vague answers signal untested scaling.
3. Update and rollback process
Ask: “How do we deploy updates with zero downtime? Can we roll back instantly if accuracy drops?”Interpretation: Production systems need smooth versioning. If updates require full rebuilds, reliability suffers.
4. Support model
Ask: “When production fails at 3 a.m., who do we reach? Engineering or tier-1 support?”Interpretation: If response time is slow, you absorb operational risk alone.
5. Migration and data portability
Ask: “Can we export raw audio, transcripts, vocabularies, and configs in open formats?”Interpretation: If the vendor cannot guarantee portability, expect painful switching costs.
Answers like “We’ll need to get back to you on GPU specs” or “Custom vocabulary takes six weeks” signal fragility you’ll end up owning.
Migration Patterns That Work in Production
Successful enterprises rarely jump to full local deployment immediately. They follow a staged approach that reduces risk without delaying ROI.
Hybrid architecture is the most common pattern. Latency-sensitive workloads such as streaming transcripts and IVR interactions stay on premise. Overnight analytics and large-batch jobs run in the cloud for elasticity. A 70/30 split between internal and cloud workloads is typical.
Migration timelines follow predictable phases:
- Months 1–3: deploy initial pilot (1,000 hours monthly)
- Months 3–9: scale to 10,000 hours
- Months 9–12: move high-volume regions fully internal
Each stage validates performance, scaling behavior, and operational procedures before committing deeper capital investment.
Failover architecture ensures continuity. Internal clusters serve as primary systems, while cloud endpoints provide automatic backup during maintenance windows or unexpected failures. Geographic expansion begins in cloud regions, then transitions on premise once volume justifies dedicated hardware.
Build on Production Infrastructure, Not Vendor Promises
Your deployment decision rests on three tangible forces: regulatory exposure, latency expectations, and volume economics. When data must stay inside your perimeter, when sub-100 ms response times define user experience, and when monthly transcription surpasses 50,000 hours, on-premise infrastructure stops being optional and becomes operational necessity. HIPAA and GDPR enforcement depend on provable control of data, and local processing satisfies those requirements without prolonged external audits.
The build-versus-buy choice shapes your engineering budget. Productionizing open source demands months of GPU tuning and ongoing maintenance. Commercial solutions shift that burden while providing predictable updates, support paths, and integration stability.
The five evaluation pillars remain constant: infrastructure, accuracy, flexibility, cost, and compliance. Require benchmarks under real load, container images that run across environments, and clear migration paths. Many enterprises begin with Docker in a private VPC, then expand to dedicated GPU clusters as volume stabilizes, keeping cloud elasticity for unpredictable traffic.
If compliance is non-negotiable, latency must stay below 100 ms, or monthly transcription exceeds 100,000 hours, Deepgram’s on-premise deployment provides proven infrastructure validated across healthcare, financial services, and large-scale contact center environments. Test it against your audio to confirm accuracy and capacity planning before rollout.
Ready to deploy production-grade speech-to-text on premise? Sign up for a free Deepgram Console account and get $200 in credits. Or schedule a technical workshop with our engineering team to review your infrastructure requirements and compliance constraints.


