{
  "generator": "helium",
  "id": "helium-voice-audio-heliox",
  "status": "final",
  "note": "Heliox model (80% helium, 20% oxygen, 20 °C): the same source and f0 as the air clip; resonances and bandwidths multiplied by the speed-of-sound ratio 1.8498 (635.0 / 343.3 m/s, ideal-gas values).",
  "reference": "helium-voice-audio-air.json",
  "sample_rate_hz": 48000,
  "duration_s": 2.0,
  "f0_hz": 120.0,
  "source": {
    "type": "band_limited_pulse_train",
    "tilt_db_per_octave": -12.0,
    "max_hz": 10000.0
  },
  "formants_air_hz": [
    504.8,
    1514.4,
    2524.0
  ],
  "bandwidths_air_hz": [
    60.0,
    90.0,
    120.0
  ],
  "speed_of_sound_ratio": 1.8498,
  "bandwidth_scaling": "proportional",
  "fade_in_s": 0.05,
  "fade_out_s": 0.05,
  "level": {
    "target_lufs": -28.0,
    "peak_max_dbtp": -12.0
  },
  "seed": null,
  "analysis": {
    "edge_s": 0.3,
    "max_analysis_hz": 10000.0
  }
}