CLF-C02 Cloud Technology and Services Practice Question
A company needs to verify the identity of users who call into their contact center by comparing their voice against a stored voiceprint. Which AWS service provides speaker identification from voice data?
⚠ Common exam trap
Candidates often confuse Amazon Transcribe (speech-to-text) with speaker identification, or assume Amazon Rekognition can handle audio, when in fact Rekognition is strictly for visual media (images and video).
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Amazon Connect Voice ID
Amazon Connect Voice ID is the correct AWS service for real-time speaker identification and verification using voice biometrics. It compares a caller's live voice against a stored voiceprint to authenticate their identity, specifically designed for contact center use cases within Amazon Connect.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Amazon Transcribe
Why it's wrong here
Amazon Transcribe is a speech-to-text service that uses ASR models to convert spoken audio into written transcripts, with optional features such as speaker diarization and custom vocabulary. The speaker diarization feature labels different audio segments by speaker (Speaker 1, Speaker 2), but it only differentiates between distinct voices; it does not enroll or formally verify a caller against a known identity, and it cannot determine if a particular voice belongs to a specific enrolled user. Therefore it is unsuitable for voice-based identity verification.
- ✗
Amazon Rekognition
Why it's wrong here
Amazon Rekognition is a computer vision service that automatically detects, analyzes, and compares faces, people, and objects within images and video, including face search in collections. It does not accept or process audio-only input, and even its video API analyzes extracted video frames rather than accompanying audio tracks. Consequently, it has no voiceprint enrollment or matching capability and cannot be used for audio-based caller verification.
- ✓
Amazon Connect Voice ID
Why this is correct
Amazon Connect Voice ID is a real-time, ML-powered service embedded in the Amazon Connect contact-center platform. It creates a unique mathematical voiceprint from a caller's voice during an initial enrollment call, then compares that caller's live speech against the stored voiceprint on subsequent interactions, authenticating the speaker in seconds. Because it verifies who is speaking, not just what is spoken, it lets contact centers securely replace or supplement traditional knowledge-based security questions.
- ✗
Amazon Lex
Why it's wrong here
Amazon Lex is a conversational AI service that combines automatic speech recognition (ASR) and natural language understanding (NLU) to process user utterances and respond with text or voice, powering chatbots. Its ASR converts audio to text and its NLU extracts intents and slots, but it performs no analysis of the unique physical characteristics (like vocal tract shape or pitch) needed to distinguish one speaker from another. Thus it answers what was said, not who said it.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CLF-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CLF-C02 exam.