playWaveSound("sample") referenced `pf` (pitch factor), a local binding that only exists inside playZoo / playLaser / playPercussion — not in playWaveSound's scope. Switching wavetype to "sample" threw a ReferenceError on the very first synth call, which the error display surfaced as "act: pf not defined" because the act() handler is what invokes setWave() → playWaveSound(). The pitch-factor is meaningless for a 30 ms UI-confirmation click, so drop the multiplication and use the literal 800 Hz tone. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>