Dialect Speech Data

Your Speech Model Fails on Dialects Because the Training Data Did

MSA Arabic WER: 15.79%. Dialectal Arabic WER: 57.48%. The gap is not a model problem. It is a data problem. YPAI collects dialect-level speech data from verified native speakers across 150+ languages.

150+ Languages Native Speaker Verified EU AI Act Ready
57.48%
Whisper WER on Arabic dialects
15.79%
Whisper WER on MSA - the gap is your data
34%
WER reduction with dialect-specific YPAI data
150+
Languages with dialect granularity
The Problem

Standard ASR Cannot Hear What Native Speakers Hear

Whisper and competing ASR systems are trained predominantly on broadcast-quality standard language. Real speech is dialects, accents, and constant code-switching. These are the five dialect families where models fail hardest.

Germanic Dialects

Norwegian alone has Bergen, Oslo, Stavanger, Trondheim, and Northern dialects - each with distinct phonology that standard Bokmål training data cannot represent. German splits into Swiss German, Bavarian, and Standard. Swedish varies across Stockholm, Gothenburg, and Skåne. A model trained on broadcast German fails in Zürich.

Norwegian 5+ dialects Swiss German Bavarian Swedish regional

Romance Dialects

French: Belgian vs Swiss vs Québec vs Standard. Spanish: Castilian vs Catalan vs Andalusian. Italian: Standard vs Sicilian vs Neapolitan. Each variant carries phonological shifts that collapse WER when the training set is monolithic.

3 language families · 12+ variants

Semitic Dialects

Arabic: Gulf vs Levantine vs Egyptian vs Maghrebi vs MSA. Each sub-dialect sounds completely different to a native speaker. A model that only sees MSA will hallucinate on Darija.

Code-Switching

Norwegian-English, German-Turkish, French-Arabic. Real European speech involves constant language mixing - mid-sentence switches between mother tongue and English, or between two community languages. Standard corpora ignore this entirely, flagging it as error rather than capturing it as signal.

Mid-sentence switching Labeled transitions Multi-lingual ground truth
YPAI Home Turf

Nordic Focus

Deep coverage of all Norwegian dialects, Swedish regional variants, Danish, and Finnish. The Nordics are a voice AI development hotspot (Speechmatics 2025). YPAI is headquartered in Norway with direct access to native speakers across every dialect region - from Northern Norwegian to Bergen dialect to Trondheimersk.

How It Works

From Dialect Gap to Production Accuracy

Three steps. Each one eliminates a failure mode that generic data vendors cannot address.

01

Dialect-Specific Recruitment

We do not ask contributors to self-report dialect. Linguistic reviewers verify dialect authenticity before recording begins. Each speaker is mapped to a specific dialect region, not a country-level language tag.

02

Granular Metadata

Every recording tagged with: specific dialect variant, city-level location, speaker age, gender, recording environment, and device type. Your pipeline can filter and stratify without manual review.

03

Native-Speaker QA

Every recording reviewed by a native speaker of that specific dialect. Not a generic language reviewer - a person who grew up speaking Bergen Norwegian reviews Bergen recordings. Dialect authenticity is verified, not assumed.

Data Comparison

Crowdsourced Standard Corpus vs. YPAI Dialect Data

The difference is not volume. It is granularity at every layer of the data pipeline.

Standard Corpus

Dialect Tagging

"Arabic" or "German" - country-level at best

Speaker Verification

Self-reported, unverified

Code-Switching

Ignored or flagged as transcription error

Recording Conditions

Studio / broadcast quality only

Result

89% accuracy on broadcast - collapses on real speech

YPAI Dialect Data

Dialect Tagging

Gulf / Levantine / Egyptian / Maghrebi or Swiss / Bavarian / Swabian

Speaker Verification

Linguist-verified native speaker of specific dialect

Code-Switching

Captured and labeled with transition boundaries

Recording Conditions

Multiple environments: street, home, car, office

Result

93%+ accuracy across dialect regions

Language Coverage

Dialect Data Across Three Coverage Tiers

Every tier includes dialect-level granularity, verified native speakers, and structured metadata.

Tier 1 Deep Coverage

Full dialect coverage with all regional variants. Multiple recording environments. Extensive code-switching data. Highest metadata granularity.

NorwegianSwedishDanishFinnishGermanFrenchSpanishItalianDutchPolish
Tier 2 Strong Coverage

Major dialect variants with verified speakers. Core metadata and multi-environment recordings available.

PortugueseCzechHungarianRomanianGreekTurkishUkrainianArabic (EU diaspora)
Tier 3 Available

Accessible via partner network with standard dialect tagging and speaker verification. Custom collection scoped on request.

100+ additional languages via partner network
Get Started

Close the Dialect Gap in Your ASR Pipeline

Tell us your target languages, dialect regions, and volume requirements. We will respond with a technical specification covering speaker demographics, metadata schema, and delivery format.

Technical spec within 48 hours
Sample recordings available
EU AI Act documentation included