Building the voice of
multilingual AI.
End-to-end speech data infrastructure, from scenario design to model evaluation, fully managed. One partner. One pipeline. Enterprise SLA.
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Five stages. One accountable partner.
Speech data programs are complex. Welo Data covers the full pipeline: consistent quality standards, a single point of contact, and enterprise SLAs at every stage.
Domain-specific design and controlled scripting across a broad range of speech data types — conversational dialogue, single-speaker narration, task-based prompts, prompted responses, and more. This includes defining the right recording environments and setups, specifying audio quality standards and formats, and directing performance style, whether emotional, conversational, formal, or spontaneous.
Scripted and spontaneous recordings collected across studio and remote environments, stratified by age, accent, gender, and register to match your target language profile and real-world deployment conditions.
Human transcription workflows, verbatim and normalized, with speaker diarization, timestamp alignment, and multi-speaker segmentation at scale.
Phonetic, prosodic, and disfluency labeling; emotion, intent, and sentiment tagging; with rigorous quality assurance built into every program.
Subjective listening panels that assess how natural your trained model actually sounds, to real humans, across languages and dialects.
Every dimension your model actually needs.
Our QoE panels cover the full set of perceptual dimensions that determine whether a speech model is production-ready. Not just the ones that are easy to automate.
Verified native-speaker contributors available for evaluation and collection tasks worldwide.
Enterprise-grade information security certification. Your data is handled to the highest standard.
Global secure delivery facilities for on-site collection and annotation where controlled environments are required.
Need a pilot? Many programs deliver in under two weeks.
From brief to delivery: verified native speakers, fully annotated, enterprise SLA.
Request a Speech Pilot →The difference between a vendor and a speech data partner.
Building reliable speech AI requires a partner who understands the full model development lifecycle and can maintain quality standards across languages, domains, and delivery modalities.
Coverage across 155+ locales, including low-resource, regional, and endangered language varieties that are difficult to source reliably at scale.
ISO 27001 certified with 14 secure delivery facilities and a network of partner studios globally. Sensitive programs can run in controlled on-site environments, not only remote crowdsourcing.
Automated metrics tell you how a model scores. Human listening panels tell you how it actually sounds. We run both, because the latter is what your users will experience.
500k+ contributors verified through NIMO, Welo Data’s workforce integrity platform. Every speaker is who they say they are, in the location they say they are, doing the work themselves.
Common questions. Straight answers.
We support the full range of speech AI use cases: ASR (automatic speech recognition) training and evaluation, TTS (text-to-speech) data production, voice assistant and conversational AI development, speaker verification, emotion and sentiment detection, and more. Our team works with you to scope the right collection, annotation, and evaluation approach for your model’s specific requirements.
With 100+ country-level contributor networks covering 155+ locales, we have genuine depth for languages that most providers cannot staff reliably. For low-resource languages, we work with community-embedded networks to identify and verify native speakers. We are transparent about what we can source in your target variety before any program begins.
Quality of Experience (QoE) evaluation uses human listening panels, not just automated metrics, to assess how a trained speech model actually sounds to real users. Automated accuracy scores measure whether words are correct — they cannot tell you whether a synthesized voice sounds natural, whether prosody feels right, or whether an accent is rendered authentically. QoE evaluation fills that gap, producing perceptual scores across naturalness, fluency, intelligibility, and more.
Yes. Welo Data operates 14 secure delivery facilities globally for programs that require controlled recording environments, stricter data handling conditions, or restricted access setups. These facilities are ISO 27001 certified and staffed by on-site project management teams. If your program has specific security, acoustic, or access requirements, we can discuss facility options during scoping.
For many programs, we can deliver a pilot dataset in under two weeks from an agreed brief. Timelines depend on language, volume, and annotation complexity, and we will always scope these accurately before a program begins. The goal is to get you to a validation point quickly, so you can assess data quality before committing to full-scale production.
We handle the full pipeline under a single SLA with a dedicated program team. You can also engage us for individual stages if you already have existing data or vendors handling other parts of the workflow. Either way, you get one point of contact and one quality standard throughout.
Contributor authenticity is verified through NIMO, Welo Data’s proprietary workforce integrity platform, which continuously checks that contributors are who they claim to be, operating from a confirmed location, with validated language and domain credentials. For speech programs, we go further: we are also implementing third-party tooling to detect AI-generated audio, because a verified human contributor can still use generative AI to produce speech. Our integrity checks cover both the person and the work they submit.
Ready to build a speech model that sounds like the real world?
Talk to our team about your speech program: collection, annotation, evaluation, or the full pipeline.
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