Speech & Audio
Focusing on the natural interaction frontier—training models to listen and speak like humans. From expressive synthesis to real-time dialogue, we capture the subtleties of human voice that define next-generation audio AI.
Custom Data Services
Bespoke speech and audio data collection and annotation designed around your model's specific requirements.
Expressive TTS Synthesis
Rich annotation of emotion, prosody, and breath markers that transform text-to-speech output from robotic to genuinely natural and expressive.
Acoustic Scene & Emotion Detection
Labelled audio identifying background environments and speaker sentiment, enabling models to understand not just what was said, but how and where.
Conversational AI Training Data
Training data for real-time voice systems that manage immediate, sub-second interruptions, the data layer behind natural conversational AI.
Code-Switched & Dialectal Speech
High-fidelity multilingual AI training data from niche languages and regional accents across 500 global locales, ensuring models perform for every user, everywhere.
Paralinguistic Event Labeling
Categorisation of non-verbal cues including sighs, laughter, and hesitation that fundamentally change the meaning of spoken intent for advanced audio models.
Multi-Speaker Audio Transcription
Precise speaker diarisation and transcription of overlapping, multi-party conversations, enabling models to distinguish who said what in complex real-world audio environments such as meetings, call centres, and interviews.
Case Studies
How leading AI organisations trust Appen for speech and audio training data. Read how a top automotive OEM used speech training data to power their connected car voice systems, or download the Audio Data for AI Models whitepaper for a full overview of our speech data capabilities.
Fast and Accurate Customer Insights with Large-Scale Annotation
High-volume call centre audio annotation delivering actionable insights for conversational intelligence at enterprise scale.
Creating Data That Powers ML Models for Human Conversation
Annotated conversational data enabling Dialpad’s AI to understand and transcribe natural business dialogue in real time.
Top Automotive OEM: Speech Training Data for the Connected Car
Multi-dialect speech corpus for voice-controlled in-vehicle systems across global markets.
Low-Resource Language Voice Models
Building speech datasets for underrepresented languages to enable high-quality voice AI for diverse global communities.
Insights & Resources
Expert thinking on speech and audio AI from Appen's data scientists and linguistics team. Start with What is Sociophonetics and Why It Matters for AI or explore the practical guide to multilingual NLP.
What Is Sociophonetics and Why It Matters for AI
How social context shapes pronunciation—and why speech AI must account for dialect, identity, and community to be truly inclusive.
Multilingual NLP: Code-Switching, Variants & Dialectal Expansion
The linguistic realities of code-switching and dialect variation that modern multilingual NLP must address.
Ready to build with confidence?
Talk to our team about speech and audio data solutions, from expressive TTS synthesis to dialectal speech collection across low-resource languages.