10 Top Speech Data Companies

1. Appen: Global Scale with Diverse Speech Data Solutions

Appen has long been regarded as one of the leading speech data providers, operating in over 170 countries with support for more than 235 languages and dialects. This Australian-origin company has built a strong reputation by offering scalable, high-quality speech datasets for use in AI and machine learning applications. Appen serves some of the largest technology firms globally, making it one of the most visible names among speech data services companies.

What sets Appen apart is its emphasis on ethical data sourcing, linguistic diversity, and human-validated quality. It offers tailored speech data collection, transcription, annotation, and natural language processing (NLP) support. Clients include automotive companies enhancing voice interfaces, healthcare providers developing diagnostic tools, and mobile platforms building more responsive voice assistants.

A key reason why Appen continues to lead among companies offering speech data is its use of hybrid systems that blend automated processing with crowd-sourced human validators. Their global crowd workforce, estimated at over 1 million contractors, allows for rapid data collection and annotation in a variety of environments—urban, rural, noisy, quiet—and across different demographics. This breadth ensures data sets are robust and inclusive, which is essential for building unbiased voice technologies.

For example, one project Appen supported involved creating a multilingual voice dataset for a European telecom company seeking to expand its voice AI across five markets. The company collected native speaker audio samples in diverse conditions, annotated them with precision, and delivered a final dataset that improved the telecom firm’s voice assistant accuracy by over 30%.

Despite its size, Appen has also faced scrutiny. A 2021 report from The Verge raised questions about contractor compensation and workload distribution. Appen responded with updates to its quality assurance framework and clearer guidelines for task allocation—demonstrating the importance of transparency and worker rights in speech data operations.

From a market perspective, Appen continues to adapt. In 2023, the company shifted towards enterprise-grade solutions with deeper focus on industry-specific speech data delivery. This included healthcare voice recordings for diagnostic AI and legal transcription corpora for compliance tools. Its recent push into real-time speech analytics indicates that Appen is positioning itself to meet growing demand from firms requiring immediate voice feedback for customer experience improvement.

For AI developers and data scientists, the main draw is Appen’s data volume and linguistic breadth. For academic researchers, it offers access to speech samples across underserved languages, aiding studies in language processing and speech recognition for lesser-known dialects.

To summarise, Appen stands out among leading speech data providers for its:

• Global data acquisition capabilities
• Large multilingual workforce
• Commitment to quality assurance and ethics
• Strong record of corporate partnerships

While no provider is perfect, Appen’s continued innovation and capacity to deliver complex projects make it a cornerstone among companies offering speech data.

2. Way With Words: Custom Speech Collection and Transcription Excellence

Way With Words has earned recognition as one of the most adaptable companies offering speech data, particularly for clients with highly specific or regulated requirements. With origins in the United Kingdom and South Africa, the company serves a wide array of international clients, offering custom-built speech collection projects and high-accuracy human transcription services tailored to business, academic, legal, and research sectors.

Among speech data services companies, Way With Words distinguishes itself through quality control and flexibility. It provides end-to-end management for speech data collection projects, covering everything from speaker recruitment to metadata management. A notable feature is its Speech Collection service, designed specifically for clients who need bespoke datasets that meet rigorous linguistic and technical criteria.

Unlike many providers who rely heavily on automation, Way With Words combines technology with professional human oversight to ensure accuracy and contextual integrity. This has been critical for institutions developing AI models for speech-to-text engines or conducting longitudinal linguistic studies.

Case studies show successful collaborations with education departments collecting child speech for early literacy tools, and with legal tech firms developing compliance voice analytics. Their transcription arm also supports ongoing research initiatives requiring consistent speaker identification and audio quality validation.

Way With Words also emphasises data privacy, making it one of the more trusted names among leading speech data providers. The company maintains GDPR compliance and works with clients to ensure ethical consent protocols and anonymisation processes are followed.

In a time when off-the-shelf datasets may not be sufficient, Way With Words offers a high-touch, consultative model for creating exactly the speech data you need, especially for high-stakes or niche projects.

3. Defined.ai: High-Quality AI Data Marketplaces

Defined.ai (formerly DefinedCrowd) is another of the prominent speech data services companies known for its AI-focused data marketplaces. Founded in Seattle with a global footprint, the company delivers curated speech datasets that support conversational AI, speech recognition, and NLP models.

What makes Defined.ai unique among leading speech data providers is its marketplace model. It allows clients to purchase pre-collected datasets or commission custom speech data, covering multiple languages, accents, and speech styles.

One standout project involved providing conversational datasets for an automotive firm building an in-car assistant that had to recognise regional dialects and spontaneous dialogue. Defined.ai delivered over 10,000 hours of annotated speech, improving voice command precision significantly.

Their strong commitment to ethical AI and contributor transparency also makes them a preferred option for data scientists focused on fairness in training data. Defined.ai publishes regular reports on dataset bias, making it one of the few companies offering speech data to proactively assess and share its data integrity measures.

4. LumenVox: Voice Biometrics and Speech Recognition Integration

LumenVox is one of the more specialised speech data services companies, focusing on voice biometrics, speech recognition, and secure authentication. It is often selected by financial institutions, healthcare firms, and government bodies that need to integrate voice interfaces without compromising security.

What distinguishes LumenVox from other companies offering speech data is its proprietary speech engine, which is trained using secure, client-specific voice datasets. Their biometric engine is used for voice identity verification and fraud prevention, providing solutions that are both privacy-focused and highly functional.

Case studies include secure onboarding systems for banks in North America and voice-authenticated login systems for medical record access in Europe. These demonstrate that speech data is not only useful for AI model training but can play a critical role in security ecosystems.

Their niche positioning makes LumenVox ideal for firms needing high-assurance speech applications rather than general-purpose datasets.

SpeechOcean is one of the most prolific speech data services companies operating in Asia. With over 50,000 datasets in 150+ languages and dialects, it has built a name for delivering massive speech data volumes for speech synthesis, language modelling, and transcription training.

The company is particularly well-regarded among firms looking for Mandarin, Cantonese, Thai, Vietnamese, Korean, and other Asian-language data. Its scalable infrastructure allows it to collect speech from thousands of speakers simultaneously, making it a go-to for fast, region-specific projects.

One of SpeechOcean’s strengths is its collaboration with academic institutions, which supports speech research on lesser-resourced languages. It also integrates with local mobile platforms to gather speech data in naturalistic settings.

Its role as one of the leading speech data providers in Asia cannot be understated, especially for companies expanding into multilingual or regional AI development.

Rev AI, an offshoot of Rev.com, has established itself among speech data services companies as a real-time API provider for transcription and speech recognition. While Rev.com is known for manual transcription, Rev AI focuses on automated, API-based solutions.

The platform is widely used by developers integrating transcription into apps, platforms, and software systems. One of its standout features is the combination of real-time speech processing with custom vocabulary adaptation, making it especially useful in industries with specific jargon—like law, medicine, or technical support.

For example, Rev AI partnered with a legal platform to generate custom legal vocabularies for court proceedings, improving transcription accuracy from 84% to 96%.

While not the largest dataset provider, Rev AI appeals to clients looking for speed, integration, and adaptability—qualities that matter in dynamic project environments.

TranscribeMe bridges the gap between transcription services and enterprise-grade speech datasets. It offers multi-tiered transcription accuracy levels, allowing companies to choose between 99% human-verified transcripts or faster, lower-cost hybrid options.

The company works with Fortune 500s and academic researchers alike. One notable project involved partnering with a health research institute to transcribe patient interviews and generate speaker-labelled datasets for medical NLP development.

TranscribeMe also provides voice datasets tailored to healthcare, education, and customer service, with metadata including speaker demographics, noise conditions, and timestamp accuracy. These granular options allow for deeper machine learning model training.

As one of the more versatile companies offering speech data, TranscribeMe appeals to both large-scale research projects and commercial AI ventures.

iMerit is one of the few speech data services companies to centre ethical employment and inclusivity at the heart of its business model. Based in India with global clients, it focuses on providing high-quality labelled data—both speech and visual—via a socially driven model.

iMerit has built specialised teams for tagging and annotating speech data across domains like agriculture, healthcare, and social science. Their clients include NGOs building voice-based health diagnostics for rural communities, and government agencies using voice tech for public services.

By hiring from underserved communities and investing in workforce training, iMerit redefines what it means to be a leading speech data provider. Clients benefit not only from precision, but also from a brand that aligns with social impact values.

Clickworker is a global platform that leverages a large distributed workforce to collect and annotate audio data. Often compared to Amazon Mechanical Turk, Clickworker stands out for its QA processes, project management interface, and scalable human workflows.

Their speech data services include scripted voice reading, spontaneous speech, dialect capture, and audio transcription. With over 4 million contributors worldwide, Clickworker is used by AI developers who need rapid data collection from diverse populations.

One notable example was a speech collection campaign in 30+ countries for a navigation software developer. The result was over 20,000 hours of voice commands captured in realistic driving environments—something that few speech data services companies can manage at speed and scale.

Formerly known as Lionbridge AI, TELUS International AI Data Solutions offers enterprise-grade services for companies requiring precise speech data. Their offerings include speech collection, transcription, tagging, and audio enhancement, geared primarily toward Fortune 500 clients.

The company focuses on multilingual audio, and offers data collection in compliance with HIPAA, GDPR, and other regional regulations. It’s often selected for high-volume contracts involving sensitive sectors like healthcare, telecommunications, and finance.

In a time where data protection is critical, TELUS International provides peace of mind with its controlled access policies, anonymisation protocols, and global compliance framework. It remains one of the most trusted names among leading speech data providers for high-risk applications.