Voice Integration

sensor-humor pairs with mcp-voice-soundboard to deliver spoken comedy with mood-appropriate prosody.

How it works

Each mood maps to a Piper TTS voice and 4 prosody knobs:

Knob	What it controls	Effect on comedy
length_scale	Speech speed (>1 = slower)	Dry/cynic drag; zoomer rushes
noise_scale	Expressiveness (0 = flat, 1 = animated)	Dry is monotone; chaotic is erratic
noise_w_scale	Phoneme timing variance (0 = metronomic, 1 = erratic)	Controls whether words land at even intervals
volume	Loudness	Cynic is quiet; zoomer is loud

Mood-to-voice mapping

Mood	Piper Voice	length	noise	noise_w	vol
dry	en_GB-alan-medium	1.15	0.3	0.3	0.9
roast	en_US-ryan-high	0.95	0.667	0.8	1.0
chaotic	en_US-lessac-high	0.88	0.8	0.9	1.1
cheeky	en_GB-cori-high	1.05	0.5	0.6	0.95
cynic	en_GB-alan-medium	1.25	0.2	0.2	0.8
zoomer	en_US-lessac-high	0.90	0.85	0.9	1.15

Setup

1. Install Piper voice models:

# Download to your model directory
# Required: alan-medium, ryan-high, lessac-high, cori-high

2. Start voice-soundboard with Piper:

VOICE_SOUNDBOARD_ENGINE=piper \
VOICE_SOUNDBOARD_PIPER_MODEL_DIR=/path/to/piper/models \
npm start

3. After any sensor-humor tool call, speak the result:

voice_speak({ text: result.roast, mood: "roast" })

Kokoro fallback

If VOICE_SOUNDBOARD_ENGINE is not set, the default Kokoro backend is used. Kokoro supports voice selection and speed control but not full prosody (noise_scale, noise_w_scale, volume are ignored). The comedy still works — just without the prosodic separation between moods.

Why Piper over Kokoro

Kokoro strips SSML and only respects speed + voice selection. Piper’s ONNX inference exposes all 4 prosody knobs natively via SynthesisConfig, giving real vocal differentiation:

• Dry and cynic use the same voice (alan) but cynic is measurably slower, flatter, and quieter
• Chaotic has high timing variance — words don’t land at even intervals, which reads as erratic
• Roast has natural expressiveness that gives verdict labels a confident lift
• Zoomer is fast and loud — streamer energy with brisk pacing