majiayu000 Voice Synthesis Skill
The Voice Is the Heart of the Journey
This skill handles converting SSML scripts to voice audio with psychoacoustic enhancement.
Purpose
Generate high-quality, hypnotic voice audio from SSML scripts using Google Cloud Text-to-Speech.
Production Voice Standard
Always use: en-US-Neural2-H (bright female)
| Parameter | Value |
|---|---|
| Voice ID | en-US-Neural2-H |
| Speaking Rate | 0.88x (applied by TTS engine) |
| Pitch | 0 semitones (base) |
| Enhancement | Always enabled |
Canonical Command
python3 scripts/core/generate_voice.py \
sessions/{session}/working_files/script_voice_clean.ssml \
sessions/{session}/output
This automatically:
- Uses production voice (
en-US-Neural2-H) - Applies 0.88x speaking rate baseline
- Generates both raw and enhanced output
- Outputs
voice.mp3andvoice_enhanced.mp3
Voice Options Reference
Female Voices (Recommended for Hypnosis)
| Voice ID | Character | Best For |
|---|---|---|
en-US-Neural2-H |
Bright, clear | Production standard |
en-US-Neural2-E |
Deep, resonant | Darker themes, shadow work |
en-US-Neural2-C |
Soft, gentle | Very gentle sessions |
en-US-Neural2-F |
Clear, articulate | Educational content |
en-US-Neural2-G |
Warm, approachable | Confidence, empowerment |
Male Voices
| Voice ID | Character | Best For |
|---|---|---|
en-US-Neural2-D |
Deep, authoritative | Guided pathworkings |
en-US-Neural2-I |
Warm, compassionate | Healing journeys |
en-US-Neural2-J |
Rich, mature | Wisdom, elder guidance |
Note: en-US-Neural2-A is MALE, not female.
Output Files
| File | Purpose | Use For |
|---|---|---|
voice.mp3 |
Raw TTS output | Never use directly |
voice_enhanced.mp3 |
Production voice | Always use this |
voice_enhanced.wav |
Lossless for mixing | Audio mixing input |
Voice Enhancement
The generate_voice.py script applies these enhancements:
| Enhancement | Effect |
|---|---|
| Tape Warmth | Analog saturation (25% drive) |
| De-essing | Sibilance reduction (4-8 kHz) |
| Room Tone | Gentle reverb (4% wet) |
| EQ Shaping | Presence boost, rumble cut |
Chunking System
Large scripts are automatically chunked:
- Detection: Script exceeds API byte limit
- Splitting: At natural break points (
<break time="3s"/>or greater) - Generation: Each chunk processed separately
- Concatenation: Final output seamlessly joined
Duration Verification
After generation, verify duration matches target:
# Check duration
ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 \
sessions/{session}/output/voice_enhanced.mp3
| Target Duration | Expected | Acceptable Range |
|---|---|---|
| 25 minutes | 25:00 | 23:00 - 27:00 |
| 30 minutes | 30:00 | 28:00 - 32:00 |
| 45 minutes | 45:00 | 42:00 - 48:00 |
If duration is off:
- Adjust
<break>durations in SSML - Add/remove content as needed
- Regenerate voice
Prerequisites
Before running voice synthesis:
Environment:
source venv/bin/activateGoogle Cloud Auth:
echo $GOOGLE_APPLICATION_CREDENTIALS # Should show path to credentials JSONSSML Validation:
python3 scripts/utilities/validate_ssml.py sessions/{session}/working_files/script_voice_clean.ssmlSFX Stripped:
grep -c "\[SFX:" sessions/{session}/working_files/script_voice_clean.ssml # Should return 0
Troubleshooting
| Issue | Cause | Solution |
|---|---|---|
| "Authentication failed" | Missing credentials | Check GOOGLE_APPLICATION_CREDENTIALS |
| Robotic sound | Using slow rate in SSML | Use rate="1.0", breaks for pacing |
| TTS reads "[SFX:..." | SFX markers not stripped | Use script_voice_clean.ssml |
| Chunking errors | Break points too far apart | Add <break time="3s"/> every few paragraphs |
| Duration too short | Not enough content | Add more script content |
| Duration too long | Too much content | Trim or reduce break times |
Integration with Pipeline
Before (dependencies):
- SSML script validated
- SFX markers stripped
After (next steps):
- Audio mixing with binaural and SFX
- Hypnotic post-processing
Quality Checklist
Before proceeding to mixing:
-
voice_enhanced.mp3exists - Duration within acceptable range
- No clipping (peak < 0 dB)
- No artifacts or glitches
- Pacing sounds natural
- All words clearly articulated
Related Resources
- Skill:
tier3-production/ssml-generation/(input) - Skill:
tier3-production/audio-mixing/(next step) - Serena Memory:
audio_production_methodology - Script:
scripts/core/generate_voice.py