Robert Helewka
92c45e9c4d
The speech fixture classified as LIVE_HUMAN on its first 3s window and drifted to MUSIC for every window after. I had validated only the first window and reported the fixture as verified, which overstated it: any lab result resting on that fixture — the hold-slayer scenarios above all — was proving less than it appeared to. The cause was one modelling error, not a tuning problem. `_detect_tonality` looks for an autocorrelation peak above 0.5 in the 50-1000 Hz lag range, and each syllable used a *constant* f0, which is perfectly periodic there. That scored is_tonal=True, handing the music score a free 0.3 that speech could not outrun — and the decision requires speech_score to strictly exceed music_score, so ties went to music. Real voices glide and jitter, so the periodicity never locks. The fundamental now follows a per-syllable pitch contour (rise or fall, plus ~2% cycle-to-cycle jitter), with the frequency integrated to phase rather than multiplied by t — `2*pi*f*t` is only a chirp when f is the instantaneous rate, which it is not once f0 itself moves. is_tonal is now False in every window. Two smaller fixes fell out of that: - Aspiration noise is high-passed rather than broadband. Flat noise puts energy in every Goertzel bin, so the strongest DTMF row and column both clear the detector's `total_power * 0.1` threshold and each syllable reads as a keypress. A first-difference filter leaves the 697-1633 Hz bands comparatively empty. The level is set for margin — spectral flatness lands at ~0.46, mid-way through the 0.1-0.5 band, not on an edge. - The music fixture gained two more harmonics and a recording-style noise floor. Windows straddling a chord change had a momentarily sparse spectrum and fell *below* the music score's 0.05 flatness floor, scoring as speech. All three fixtures now classify correctly in 100% of windows (music 27/27, speech 5/5, silence 2/2), and remain correct when the window is stepped by half a window — a fixture that only works on aligned boundaries would still be a trap in a live call, where the analysis window has no relationship to where the audio began. Confirmed on a real call through the lab: scenario 1003 now shows the whole hold-slayer arc, speech -> sustained music -> speech, matching the dialplan. tests/test_lab_fixtures.py guards this: it sweeps every window rather than sampling the first, which is exactly what the original validation missed, and checks the generator is byte-for-byte deterministic. It skips when the fixtures have not been generated, since they are gitignored. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
3.8 KiB
3.8 KiB