← all edge cases

Amusement → Mild genuine laughter

Evolved prompt+setting recipes to push the Amusement LoRA toward the extreme. Fitness combines the EmoNet target (Amusement), vocal-burst blend, genuineness and DSP proxies (loudness, pitch/jitter, spectral flatness for screams, 3–9 Hz amplitude tremor for crying/shivering).

Best fitness 0.464 vs edge-prompt-without-LoRA 0.406 (LoRA lift +0.058) vs neutral 0.090. Winning λ ≈ 1.5; top burst-tags: <warm laughter> (5), <giggles> (5), <chuckles> (4), <laughs softly> (2).
Method & reproducibility — how the evolution ran
Base model: laion/moss-tts-local-transformer-4.55b-voice-acting-v2 · LoRA: the matching v3 emotion LoRA (rank 32) applied via PEFT adapter scaling at strength λ.
Algorithm: genetic search — population 24, 6 generations, elitism (top 8). Each genome is generated best-of-4; its fitness is a multi-objective score for the edge case = the EmoNet target + vocal-burst blend + genuineness + DSP proxies (RMS loudness, median pitch, pitch jitter, spectral flatness for screams, 3–9 Hz amplitude tremor for crying/shivering); the best-fitness candidate represents the genome. Offspring = 60% crossover of two elites + mutation, 40% mutation of one elite.
Genome (what evolves): the GENERAL voice description, the SCRIPT cue, the inline vocal-burst tags (e.g. <screams>, <laughs softly>, <sobbing>), the carrier line, the LoRA strength λ, and the sampling params (temperature, top_p, top_k).
Mutation operators: 30% new description, 20% add/remove a vocal-burst tag, 15% swap carrier, 17% jitter λ by ±0.25/0.5, then temperature jitter.
LoRA on vs off: the two LoRA OFF cards are baselines with the adapter disabled (λ=0) — a neutral prompt and the best edge prompt without the LoRA. Every LoRA ON hall-of-fame recipe was generated with the LoRA active at the evolved λ shown on the card.

Baselines — LoRA disabled

NEUTRAL promptLoRA OFF (λ=0)
fit 0.090 · emo -0.00 · blend 0.20 · genu 0.08 · WER 0.09 · rms 0.105 · pitch 126Hz · jit 0.75 · flat 0.045 · trem 0.17 · 9.12s
EDGE promptLoRA OFF (λ=0)
fit 0.406 · emo 0.11 · blend 0.80 · genu 0.33 · WER 0.00 · rms 0.094 · pitch 249Hz · jit 0.79 · flat 0.078 · trem 0.11 · 7.68s
GENERAL: A genuine voice, gentle, pushed to the extreme edge of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "Oh, that is priceless."
<laughs softly><warm laughter>

Hall of fame — top 9 evolved recipes (all generated WITH the LoRA active)

#1LoRA ON · λ=1.0 (100%)
fit 0.464 · emo 0.51 · blend 0.32 · genu 0.58 · WER 0.20 · rms 0.081 · pitch 359Hz · jit 0.37 · flat 0.012 · trem 0.16 · 7.04s
GENERAL: A genuine voice, easy, at the extreme of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "You actually did that? Unbelievable."
<chuckles><warm laughter> · LoRA strength λ 1.0 · temp 1.0 · top_p 0.95 · top_k 40
#2LoRA ON · λ=1.5 (150%)
fit 0.464 · emo 0.63 · blend 0.43 · genu 0.28 · WER 0.00 · rms 0.049 · pitch 374Hz · jit 0.52 · flat 0.037 · trem 0.18 · 11.68s
GENERAL: A easy voice, delighted, at the extreme of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "I can't believe you just said that."
<giggles><warm laughter> · LoRA strength λ 1.5 · temp 1.2 · top_p 0.95 · top_k 40
#3LoRA ON · λ=1.5 (150%)
fit 0.442 · emo 0.26 · blend 0.84 · genu 0.58 · WER 0.80 · rms 0.047 · pitch 418Hz · jit 0.57 · flat 0.013 · trem 0.30 · 4.48s
GENERAL: A easy voice, soft, at the extreme of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "You actually did that? Unbelievable."
<giggles><warm laughter> · LoRA strength λ 1.5 · temp 1.1 · top_p 0.9 · top_k 40
#4LoRA ON · λ=1.5 (150%)
fit 0.433 · emo 0.37 · blend 0.48 · genu 0.46 · WER 0.00 · rms 0.053 · pitch 372Hz · jit 0.58 · flat 0.071 · trem 0.18 · 10.88s
GENERAL: A delighted voice, soft, at the extreme of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "I can't believe you just said that."
<giggles> · LoRA strength λ 1.5 · temp 1.1 · top_p 0.9 · top_k 40
#5LoRA ON · λ=0.75 (75%)
fit 0.421 · emo 0.18 · blend 0.68 · genu 0.46 · WER 0.00 · rms 0.133 · pitch 407Hz · jit 0.68 · flat 0.083 · trem 0.20 · 7.36s
GENERAL: A warm voice, gentle, pushed to the extreme edge of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "Stop it, you're too much."
<chuckles><laughs softly> · LoRA strength λ 0.75 · temp 1.1 · top_p 0.95 · top_k 40
#6LoRA ON · λ=1.5 (150%)
fit 0.415 · emo 0.54 · blend 0.32 · genu 0.37 · WER 0.00 · rms 0.054 · pitch 361Hz · jit 0.54 · flat 0.060 · trem 0.14 · 11.2s
GENERAL: A genuine voice, warm, at the extreme of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "You actually did that? Unbelievable."
<giggles><warm laughter> · LoRA strength λ 1.5 · temp 1.1 · top_p 0.9 · top_k 40
#7LoRA ON · λ=1.0 (100%)
fit 0.408 · emo -0.00 · blend 0.88 · genu 0.39 · WER 0.00 · rms 0.122 · pitch 380Hz · jit 0.60 · flat 0.093 · trem 0.17 · 9.12s
GENERAL: A soft voice, easy, pushed to the extreme edge of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "Oh, that is priceless."
<laughs softly><chuckles> · LoRA strength λ 1.0 · temp 1.0 · top_p 0.9 · top_k 25
#8LoRA ON · λ=1.0 (100%)
fit 0.403 · emo 0.60 · blend 0.45 · genu 0.45 · WER 0.80 · rms 0.057 · pitch 541Hz · jit 0.29 · flat 0.028 · trem 0.17 · 4.16s
GENERAL: A warm voice, delighted, at the extreme of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "You actually did that? Unbelievable."
<chuckles><warm laughter> · LoRA strength λ 1.0 · temp 1.0 · top_p 0.95 · top_k 40
#9LoRA ON · λ=1.5 (150%)
fit 0.381 · emo 0.64 · blend 0.55 · genu 0.41 · WER 1.00 · rms 0.077 · pitch 541Hz · jit 0.50 · flat 0.035 · trem 0.23 · 5.92s
GENERAL: A easy voice, delighted, at the extreme of laugh. SCRIPT: (chuckling warmly, amused, breaking into gentle laughter) "Stop it, you're too much."
<giggles> · LoRA strength λ 1.5 · temp 1.1 · top_p 0.9 · top_k 40