Day 5: Analyzing Voice Emotion with VAD + HEAR #emotionai #aivoice

SEO Title: Day 5: Analyzing Voice Emotion with VAD + HEAR #emotionai #aivoice
Focus Keyphrase: AI lie detector
Meta Description: Learn how to add voice emotion analysis to your AI lie detector app using VAD and HEAR models. Detect vocal stress and hesitation for more accurate detection.

Table of Contents

Let’s Listen for the Lie: Voice-Based Emotion Detection

Up to now, your AI lie detector has focused on what was said. Today, we focus on how it was said — analyzing vocal tone, stress, and hesitation using open-source tools like webrtcvad and HEAR 2021 models.

Step 1: Install Required Packages


pip install webrtcvad librosa torchaudio soundfile

Step 2: Basic Voice Activity Detection (VAD)

We use webrtcvad to detect moments of silence or hesitation — often signs of uncertainty.


import webrtcvad
import wave

def detect_voice_pauses(wav_path):
    vad = webrtcvad.Vad(2)  # 0-3: more sensitive = 3
    wf = wave.open(wav_path, 'rb')
    frames = wf.readframes(wf.getnframes())

    pause_count = 0
    frame_duration = 30  # ms
    bytes_per_frame = int(wf.getframerate() * frame_duration / 1000) * 2

    for i in range(0, len(frames), bytes_per_frame):
        frame = frames[i:i+bytes_per_frame]
        if not vad.is_speech(frame, wf.getframerate()):
            pause_count += 1

    return pause_count

Step 3: Optional – Use HEAR Emotion Model

If you want to go deeper, try HEAR models for deeper embeddings + emotion classifiers.


# This requires PyTorch + pre-trained audio model (like PANNs or YAMNet)
# https://github.com/neuralaudio/hear-eval-kit

Step 4: Return Emotion Clues in Flask


@app.route('/api/voice', methods=['POST'])
def receive_audio():
    ...
    pause_score = detect_voice_pauses("latest_input.wav")
    ...
    return {
        "transcript": transcript["text"],
        "analysis": result,
        "pauses_detected": pause_score
    }

Why Vocal Emotion Analysis Matters

People often say “I’m fine” — but their voice might betray stress or hesitation. Your AI lie detector now detects emotional tone mismatches, boosting credibility scoring beyond just language.

Coming Tomorrow

In Day 6: Merging Emotion + GPT Analysis into One Score #trustscore #fusionai, we’ll fuse both semantic and emotional signals into a unified “truth probability” meter.

Tags: #AIUX #VoiceAI #EmotionDetection #LieDetection

Post Views: 60