Audio Generation
Documentsaudio-generationAudio Generation is an Agent Skill for documents published in the massgen/MassGen repository on GitHub: a SKILL.md instruction file an AI agent can load to do this task.
Guide to audio generation and understanding in MassGen. Covers text-to-speech, music, sound effects, and audio understanding across ElevenLabs and OpenAI backends.
How to use this skill
Bring this guide into your coding agent with a prompt tailored to the tool you use.
- Open your project in Codex.
- Copy and paste the prompt below.
- Review files and risks before approving any action.
Inspect the Agent Skill at https://github.com/massgen/MassGen/blob/HEAD/massgen/skills/audio-generation/SKILL.md and all supporting files. Report provenance, permissions, scripts, dependencies, and security risks. Propose an exact installation into .agents/skills/audio-generation, but wait for my approval before writing files or running scripts.
Copying this prompt does not install or run the skill. Review third-party files before use.
Audio Generation
Generate audio using generate_media with mode="audio". Supports speech (TTS), music, and sound effects. ElevenLabs is preferred when available, with OpenAI as fallback.
Quick Start
# Text-to-speech (auto-selects ElevenLabs if key available)
generate_media(prompt="Hello, welcome to our presentation!", mode="audio")
# With specific voice
generate_media(prompt="Hello!", mode="audio", voice="Rachel")
# Music generation (ElevenLabs only)
generate_media(prompt="Upbeat jazz piano with soft drums", mode="audio",
audio_type="music", duration=30)
# Sound effects (ElevenLabs only)
generate_media(prompt="Thunder rolling across a mountain valley", mode="audio",
audio_type="sound_effect", duration=5)
Audio Types
| Type | Backends | Description |
|---|---|---|
"speech" (default) | ElevenLabs, OpenAI | Text-to-speech with voice selection |
"music" | ElevenLabs only | Music generation from text prompt |
"sound_effect" | ElevenLabs only | Sound effect generation |
"voice_conversion" | ElevenLabs only | Change voice of existing audio (speech-to-speech) |
"audio_isolation" | ElevenLabs only | Remove background noise, isolate vocals |
"voice_design" | ElevenLabs only | Create a new synthetic voice from text description |
"voice_clone" | ElevenLabs only | Clone a voice from audio samples |
"dubbing" | ElevenLabs only | Translate and dub audio to another language |
Backend Comparison
| Backend | Default Model | Supports | API Key |
|---|---|---|---|
| ElevenLabs (priority 1) | eleven_multilingual_v2 | Speech, music, SFX | ELEVENLABS_API_KEY |
| OpenAI (priority 2) | gpt-4o-mini-tts | Speech only | OPENAI_API_KEY |
If ElevenLabs TTS fails, the system automatically falls back to OpenAI TTS.
Key Parameters
| Parameter | Description | Example |
|---|---|---|
prompt | Text to speak (speech) or description (music/SFX) | "Hello world!" |
voice | Voice name or ID | "Rachel", "nova", "alloy" |
audio_type | Type of audio | "speech", "music", "sound_effect" |
duration | Length in seconds (music/SFX only) | 30 |
instructions | Speaking style (OpenAI gpt-4o-mini-tts only) | "warm, reflective tone" |
audio_format | Output format | "mp3", "wav", "opus" |
Voice Quick Reference
ElevenLabs (top voices):
| Voice | Character |
|---|---|
| Rachel | Warm, conversational female |
| Sarah | Clear, professional female |
| Josh | Friendly male |
| Adam | Deep, authoritative male |
| Emily | Bright, energetic female |
OpenAI voices: alloy, echo, fable, onyx, nova, shimmer, coral, sage
Important: prompt vs instructions
For speech, prompt is the literal text to speak. Style guidance goes in instructions:
# CORRECT: prompt = text to speak, instructions = how to speak it
generate_media(
prompt="Welcome to the annual report presentation.",
mode="audio",
voice="alloy",
instructions="warm, reflective tone with measured pacing",
backend_type="openai"
)
# WRONG: Don't put style instructions in prompt
generate_media(prompt="Say this warmly: Welcome...", mode="audio") # Bad!
instructions only works with OpenAI gpt-4o-mini-tts. ElevenLabs uses voice selection for tone.
Audio Understanding
Use read_media (not generate_media) to analyze existing audio:
read_media(path="recording.mp3", prompt="Transcribe and summarize this audio")
Need More Control?
- Full ElevenLabs voice catalog (28+ voices): See references/voices.md
- Music and sound effects details: See references/music_and_sfx.md
- Advanced audio capabilities (voice conversion, cloning, isolation, dubbing): See references/advanced.md