Question: In a short analytical response, explain how a spoken message is processed by feature extraction, sound-unit recognition, and final transcription. State the role of each stage.

Sample answer: The first stage converts the audio into manually designed MFCC features, which are intended to preserve information about the spoken content while reducing sensitivity to details such as the speaker's pitch. The second stage analyzes those features to identify phonemes, the small sound units that make up speech. The final stage takes the phoneme sequence and turns it into written text. In this way, the system moves from raw speech to features, from features to phonemes, and from phonemes to a transcript.

Key points:

• MFCC features are designed to represent spoken content.
• MFCC features reduce emphasis on properties such as pitch.
• The phoneme stage identifies basic sound units from the audio.
• The final stage converts the phoneme sequence into text.
• The stages operate in a fixed order.

Rubric: A strong response should explain all three stages accurately, keep the sequence in order, distinguish the purpose of each stage, and describe the progression from audio to transcript without adding extra functions.