Audio & Speech Data Evaluation for ASR, TTS, and Voice AI

Validate speech model outputs for accuracy, naturalness, and global performance – with expert human review at scale.

LXT’s speech data evaluation services help you assess the real-world performance of automatic speech recognition (ASR), text-to-speech (TTS), and voice-based AI systems. From word error rate to emotional tone, we deliver multilingual, high-precision insights that help your models perform better – everywhere.

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Why leading AI teams choose LXT for audio & speech data evaluation

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Human-in-the-loop accuracy

Trained reviewers evaluate intelligibility, fluency, and alignment with expected output – improving model reliability across applications.

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Speech naturalness & pronunciation scoring

Assess prosody, clarity, emotion, and speaker identity in TTS and synthetic speech outputs.

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Accent & dialect coverage

Validate performance across diverse accents, dialects, and multilingual locales (1,000+ supported).

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Bias & fairness detection

Identify demographic or linguistic disparities in ASR or TTS model behavior.

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Robustness testing

Evaluate audio performance under noise, overlapping speech, interruptions, or emotional variance.

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Enterprise-grade data security

Secure environments and facilities protect sensitive audio, model outputs, and use cases.

Our audio & speech data evaluation services include:

LXT’s audio and speech data evaluation services span all key post-training checkpoints – from accuracy to safety and user experience.

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ASR evaluation

Evaluate word error rate (WER), semantic match, punctuation accuracy, and intent recognition across languages and accents.

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Speech synthesis / TTS evaluation

Human raters assess naturalness, pronunciation, prosody, and overall listening experience.

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Voice assistant testing

Validate system responses, speaker interaction flow, and intent detection in real-world scenarios.

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Wakeword & keyword spotting

Measure detection accuracy, latency, and false reject/accept rates in varied acoustic environments.

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Multilingual speech testing

Evaluate performance across 1,000+ languages and dialects – with cultural sensitivity and local QA.

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Audio classification tasks

Validate emotion detection, speaker ID, language tags, and domain-specific audio features.

LXT's audio & speech data evaluation project process

Every project follows a transparent, structured workflow – tuned for precision, scale, and flexibility.

requirements analysis for human-in-the-loop services

Tell us about your model type, target languages, output formats, and evaluation goals. Based on your input, we’ll discuss implementation options with you and provide a detailed quote.

human-in-the-loop workflow design

We create the evaluation workflow to match your specifications — including task types, scoring methods (e.g., WER, MOS, Likert), and clear reviewer guidelines.

pilot testing human-in-the-loop services

We assign trained, vetted reviewers based on language, accent, and domain expertise — such as linguists for speech synthesis or native speakers for ASR testing.

expert onboarding for human-in-the-loop services

We run a pre-test using a small sample of your data. This lets us verify that the evaluation setup works as intended — and gives you a chance to review the output. If needed, we adjust the workflow, tasks, or guidelines before scaling up.

production deployment of human-in-the-loop services

Human reviewers evaluate model outputs at scale, with multi-layer QA, spot checks, and audits throughout the process.

secure delivery of human-in-the-loop outputs

Final results — including scores, reviewer feedback, and QA metrics — are delivered via secure transfer, dashboard, or API.

continuous improvement for human-in-the-loop services

If needed, we support additional evaluation rounds for updated models, new locales, or expanded use cases.

Industries & use cases for audio & speech evaluation services

LXT supports speech evaluation across high-stakes, high-volume use cases:

image data collection in the automotive sector

Technology & GenAI

ASR and TTS evaluation for voice assistants and LLM integrations

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Automotive

In-car voice UX testing across languages, accents, and environments

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Healthcare

Medical voice transcription or speech-enabled app validation

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Customer Support

Contact center ASR tuning and intent validation

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Finance & Insurance

Voice authentication, call compliance, and speech analytics

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Public Sector

Accessibility, eKYC, and speech recognition in multilingual settings

Annotation & Enhancement - AI Data

Secure services for
audio & speech data evaluation

LXT embeds rigorous security and compliance into every audio evaluation workflow.

  • ISO 27001 certified

  • GDPR and HIPAA aligned

  • NDA-supported engagements and custom contracts

  • 5 Secure facilities for highly sensitive model data

  • Role-based access, audit logs, encrypted workflows

Further validation & evaluation services

Speech data evaluation is one part of building AI you can trust. LXT offers a full suite of validation and evaluation services to ensure both your training data and deployed model outputs meet high standards for accuracy, fairness, and safety — across modalities and languages.

AI data validation & evaluation

Your central hub for all LXT services that verify the quality of data and model outputs – covering everything from pre‑training dataset checks to full-scale model evaluation across text, audio, image, and video.

AI data validation & evaluation

Training data validation

Confirm that your datasets are balanced, accurate, and representative – before model training begins.

Training data validation

AI model evaluation

Evaluate the outputs of generative models, classifiers, and assistants for accuracy, safety, and fairness – in text, speech, image, and video.

AI model evaluation

Search relevance evaluation

Measure how well your search system returns and ranks results that match user intent – with human evaluation across languages, regions, and content types.

Search relevance services

Human in the loop

Add expert human review to high-risk stages of your AI development — from labeling to continuous QA.

Human in the loop services

RLHF services

Train reward models with expert preferences to guide model behavior toward alignment and helpfulness.

RLHF services

Supervised fine-tuning

Provide structured, high-quality data to teach models how to generate accurate, context-aware responses.

Supervised fine-tuning

LLM red teaming & safety

Identify refusal breakdowns, toxic outputs, and jailbreak vulnerabilities through targeted stress testing.

LLM red teaming & safety

Prompt engineering & evaluation

Analyze and improve prompt performance to boost consistency, reduce hallucinations, and control tone or bias.

Prompt engineering
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FAQs on our LXT audio & speech data evaluation services

We evaluate ASR, TTS, voice assistants, keyword spotting, and speech-based classifiers — across languages, devices, and domains.

We support MOS, WER, CER, subjective ratings (e.g., naturalness, clarity), task success, latency, and custom rubrics tailored to your goals.

Yes. We offer secure facilities, NDA-based workflows, and restricted-access setups. Ideal for confidential or regulated speech content.

We deliver scored outputs, reviewer notes, QA reports, and summaries — via secure file delivery, dashboard access, or API integration.

Pricing depends on languages, volume, complexity, turnaround speed, and security needs. We provide custom quotes based on your scope.

Ready to evaluate your audio & speech model outputs with confidence?
Ensure your ASR, TTS, and voice AI systems deliver accurate, natural, and fair results – verified by human experts.

Start your audio & speech data evaluation project today.