Case study
Voice data that came back.
A client needed roughly 500 hours of US English voice data with specific requirements on sample diversity, voice characteristics, and security — inside a budget that did not flex.
~500 hours - English (US) - reviewed quality
Project overview
What landed, and what made it hard.
A client needed roughly 500 hours of US English voice data with specific requirements on sample diversity, voice characteristics, and security — inside a budget that did not flex.
Delivery snapshot
Voice data, 500 hours
- Client
- confidential AI product company
- Service
- Voice data collection
- Volume
- ~500 hours
- Language
- English (US)
- Client rating
- reviewed quality
Why this mattered
Outcome before process.
That combination is the ordinary shape of speech data work and it is where most engagements quietly degrade. Diversity costs money. Security controls cost money. A fixed budget pushes a vendor toward the cheapest available speakers, and the dataset narrows without anyone deciding that it should.
Collection ran through the client's own mobile recording application, which meant the workflow had to fit their tooling rather than ours, with privacy compliance handled inside their environment.
MoniSa handled the work under ISO 9001:2015 for process control and ISO 27001:2022 for information handling. ISO 17100:2015 is scoped to translation, so it is not claimed for this work.
The outcome that mattered commercially was not the hour count. It was that the client returned with follow-on work, including rare-language engagements — converting a single project into a continuing relationship.
The problem to solve
Why the work was difficult, and what MoniSa changed in-flight.
Voice data has a diversity requirement that a raw hour count cannot express. 500 hours from a narrow speaker pool trains a model that works for that pool. The specification named sample diversity and voice characteristics precisely because the count alone would not have protected the dataset.
The challenge
The problem to solve
Budget was a stated constraint rather than a background pressure. The engagement required balancing collection quality against cost explicitly, which is a harder brief than either "cheapest" or "best" and one where the failure is invisible until model performance drops.
Privacy compliance shaped the workflow. Voice data is personal data. Collection through the client's mobile application meant security measures had to operate inside their app environment and their consent flow, not around it.
Working inside a client's own tooling removes a vendor's usual levers. There is no option to substitute a familiar recording pipeline or QC harness; the quality controls have to be built to fit what the application already does.
The QC burden in voice work is also different from text. A sample can be linguistically perfect and technically unusable — background noise, clipping, inconsistent microphone distance, wrong format. Both layers have to be checked, and only one of them is audible to a casual listener.
For buyers, the practical checks are: who defines speaker diversity and how it is evidenced, where consent and personal data are held, what the technical rejection criteria are, and who bears the cost of re-recording.
Operating response
What MoniSa changed
Collection ran through the client's mobile recording application, keeping voice data and consent inside the environment the client already controlled rather than moving personal data into a second system.
- Client-side tooling Collection ran inside the client's own mobile recording application, so voice data and consent never moved into a second environment.
- Privacy by design Security controls for personal data were part of the collection design rather than a review applied after the recordings existed.
- Two-layer QC Samples were checked against technical specification and linguistic quality, because a recording fails on format as completely as on content.
- Budget held without narrowing the pool Commercial terms were negotiated so cost pressure did not quietly reduce speaker diversity — the usual hidden cost of a fixed-budget speech project.
Results
Measured outcomes from this engagement.
Roughly 500 hours were collected at a reviewed quality client satisfaction rating, inside the budget constraint that framed the engagement.
| Volume collected | ~500 hours |
|---|---|
| Language | English (US) |
| Client satisfaction | reviewed quality |
| Commercial outcome | Extended into follow-on engagements |
| Follow-on scope | Included rare-language work |
Selection logic
What protected the result.
The selection came down to whether MoniSa could source and review the work at standard, and whether that would hold across the full run.
Why the fit was real
Why the fit was real
The work required collection discipline inside the client's own tooling and privacy environment, with quality held against a budget that could not move.
What decided the result
What decided the result
Protecting speaker diversity under cost pressure is what made the dataset usable — and what earned the follow-on rare-language scope.
What buyers can reuse
What buyers can reuse
- Hour count is not dataset quality. Ask how speaker diversity is defined, evidenced, and protected when budget tightens.
- Voice data is personal data. Confirm where recordings and consent are held, and who is accountable if the collection tooling belongs to the client.
- Technical rejection criteria should be written before collection. Noise, clipping, microphone distance, and format fail a sample as completely as content does.
- A fixed budget is a specification, not a background condition. Ask explicitly what a vendor will trade away to meet it.
- Repeat scope is a better quality signal than a satisfaction rating. Ask which engagements were extended and whether the follow-on work was harder than the original.
- A useful speech brief names the language variety, speaker diversity requirements, technical specification, consent and storage path, and the re-record cost owner.
- Approximate volumes reported as approximate are a good sign. Round numbers in speech collection usually describe a target rather than a delivery.
Continue from this proof
Useful comparisons for the same problem.
Use these links to compare the case with the matching service, buyer guide, and language coverage.
Mapped context
Service and buyer context
Languages named
Examples referenced in the engagement.
- English (US)
- Voice data collection
- Privacy-compliant recording
- Rare language follow-on
More proof
Related proof
Compare this case with Device voice data across 30 languages and Voice recording with first-pass QA to judge whether the operating pattern fits your brief.
case evidence
Nearest proof pattern.
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Action. MoniSa deployed a small stable four-person team working inside the partner's own production and review workflow.
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Buyer questions
Ask the questions weak vendors avoid.
Short answers for buyers checking fit, coverage, quality method, and next-step readiness.
What was delivered on this engagement?
Volume collected: ~500 hours. Language: English (US). Client satisfaction: reviewed quality
What control kept the work stable?
Protecting speaker diversity under cost pressure is what made the dataset usable — and what earned the follow-on rare-language scope.
Where should similar work go next?
Use AI data services for the delivery model, Speech data collection buyer guide for buyer-side evaluation, and the contact page for a scoped brief.
Similar brief
Send the constraint behind the metric.
A useful follow-up to a case study names the language mix, review model, deadline, and what proof your buyer team needs before approval.
Production-ready brief
01Closest matching challenge from this case02Language pair, dialect, and script coverage03Volume, cadence, or hours to deliver04Reviewer model and acceptance criteria05Security or platform constraints06Proof needed for stakeholder approvalCapability at a glance
The answers most briefs open by asking for.
Buyers rarely start with who we are. They start with a list of fields to fill. Here are ours, so the first email can be about the work instead.
- Languages and locales
- 300+ languages and 4,500+ dialects, quoted per locale rather than per language — because the dialect decides whether a dataset is usable, whether a market accepts a release, and which specialist the work goes to.
- Specialist network
- 110,000+ verified language specialists — linguists, annotators, and reviewers — plus voice talent and subtitlers, matched to the language, domain and task before assignment.
- Capacity and mobilisation
- Named availability confirmed per pair before scoping. Coverage is reported as staffed today or needing a recruitment window, in writing, before a launch date or release window is agreed.
- Sourcing constraints
- Specialists can be sourced against geographic, residency, locale and demographic requirements — including native-only, in-country, and speaker-diversity quotas where a data programme demands them.
- Deliverables and specs
- Work is delivered to the receiving specification: structured formats and schemas for data and annotation work, and timed-text, audio and platform conformance for media — subtitle reading speed, line limits, cue timing, channel and sample-rate requirements included.
- Comparable work
- 62 documented case studies stating the scope, the constraint that made it difficult, and the measured result — across AI data programmes, partner overflow, and media releases. 2,000+ AI projects delivered and 1,000+ brands served since 2015.
- Certifications
- ISO 9001:2015 quality management, ISO 27001:2022 information security, and ISO 17100 translation services — scoped to translation specifically, and stated that way rather than implied across every line.
- Commercial basis
- Quoted in the unit the work is measured in — per word, per audio hour, per approved hour, per finished minute, per batch, per item — with what the unit includes stated alongside it, whether the quote is for you or for a client you quote onward.
Need this against your own template? Convert your scope between units and check the deadline, then send the brief with your language list, content type, volume and deadline, and the acceptance criteria you will judge the output against — those four decide feasibility, and the reply addresses them directly.