Machine Learning

Implementing Speech-to-Text with Amazon Transcribe - Real-Time Conversion and Custom Vocabularies

Provides both batch and real-time speech-to-text transcription, with custom vocabularies to improve accuracy for industry-specific terms. Also covers quality management for contact centers with Call Analytics.

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Transcribe's API Suite

Transcribe is an automatic speech recognition (ASR) service that converts speech to text. The batch API asynchronously processes audio files stored in S3 (MP3, MP4, WAV, FLAC, etc.) and returns transcription results in JSON format. The streaming API provides real-time speech-to-text via WebSocket or HTTP/2, generating text with latencies of just a few hundred milliseconds. It can be used for live broadcast subtitles, real-time meeting transcription, and real-time agent assist in contact centers. Pricing is pay-as-you-go based on the seconds of audio processed, with up to 60 minutes per month included in the free tier.

Customization for Improved Accuracy

Custom vocabularies let you register industry-specific technical terms, product names, personal names, and other words that the standard model may not recognize accurately. You define words, pronunciations (IPA), and display forms in a table format and apply them to transcription jobs. For example, registering drug names and disease names in the medical field, or service names and protocol names in IT, significantly improves accuracy. Custom language models provide even more advanced customization by training on domain-specific text data (meeting minutes, manuals, FAQs) to build a language model specialized for that domain.

Call Analytics and Contact Center Applications

Transcribe Call Analytics is a feature specialized for contact center call analysis. In addition to call transcription, it automatically performs per-speaker sentiment analysis (positive, negative, neutral), call interruption detection, and silence duration measurement. The categories feature lets you define rules based on keywords and phrases to automatically classify calls. For example, you can automatically flag calls containing keywords like "cancellation" or "complaint" and route them for supervisor review. Automatic content redaction masks PII such as credit card numbers and social security numbers from transcription results. For a systematic study of transcription, related books on Amazon are also a helpful reference.

Transcribe Pricing

Transcribe pricing is based on the seconds of audio processed. Batch transcription costs approximately $0.00024 per second (approximately $0.0144 per minute), with up to 60 minutes per month included in the free tier. Streaming transcription costs approximately $0.00024 per second. Call Analytics adds an analysis fee of approximately $0.02 per minute on top of the standard transcription cost. There is no additional charge for using custom vocabularies, but custom language model training is billed separately. For large volumes of audio files, use the batch API for asynchronous processing and optimize costs with an event-driven pipeline using S3 and Lambda.

Summary

Transcribe is an ASR service that provides both batch and real-time speech-to-text transcription. Custom vocabularies and language models improve domain-specific accuracy, and Call Analytics automates quality management for contact centers. An event-driven architecture combining S3 and Lambda enables building automated transcription pipelines triggered by audio file uploads.

Related Services

Amazon TranscribeA high-accuracy speech recognition service that automatically converts audio to textAmazon S3A scalable object storage serviceAWS LambdaA serverless compute service that runs code without server management

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