{
 "page": "/fix-zoom-audio/",
 "source": "Verified before/after set built 2026-11-03 (diffio-4.6-pro via the public API)",
 "samples": [
  {
   "id": "zoom-01",
   "type": "synthetic",
   "label": "Simulated video call: clean speech (LibriTTS, CC BY 4.0) shaped like a laptop microphone, placed in a real measured hotel-room impulse response (BUT Speech@FIT Reverb Database, CC BY 4.0) with a real air-conditioner recording (by sonically_sound, Freesound, CC0), then sent through the Opus codec at 6 kbps with bursty packet loss filled in by the decoder's concealment. Restored with Diffio 4.6 Pro. Both clips are loudness-matched for playback.",
   "claimable_impairments": [
    "compression artifacts/dropouts",
    "thin telephone sound"
   ],
   "sources": [
    {
     "role": "clean speech",
     "title": "LibriTTS test-clean speaker 6829, utterances 6829_68769_000056_000001 to 6829_68769_000056_000007",
     "author": "LibriTTS (Zen et al., 2019), from a public-domain LibriVox reading",
     "url": "https://www.openslr.org/60/",
     "license": "CC BY 4.0",
     "license_url": "https://creativecommons.org/licenses/by/4.0/",
     "utterance_ids": [
      "6829_68769_000056_000001",
      "6829_68769_000056_000003",
      "6829_68769_000056_000005",
      "6829_68769_000056_000006",
      "6829_68769_000056_000007"
     ],
     "transcript": "He is supposed to sign all the checks of the concern. I was bookkeeper, so it was easy to get a blank check and forge the signature. I discovered and put out a fire that would have destroyed the whole plant. But Marshall never even thanked me. He only discharged the man who was responsible for the fire.\"",
     "join": "consecutive sentences of one paragraph joined with 0.35s of digital silence"
    },
    {
     "role": "room impulse response",
     "title": "BUT Speech@FIT Reverb Database, room R112 (hotel room, about 40 m3)",
     "author": "Brno University of Technology, Speech@FIT (Szöke et al., 2019)",
     "url": "https://speech.fit.vut.cz/software/but-speech-fit-reverb-database",
     "license": "CC BY 4.0",
     "license_url": "https://creativecommons.org/licenses/by/4.0/",
     "changes": "truncated to 1.0 s with a 50 ms fade-out; aligned to the direct-path peak"
    },
    {
     "role": "impairment recording",
     "title": "Air Conditioner",
     "author": "sonically_sound",
     "url": "https://freesound.org/people/sonically_sound/sounds/625224/",
     "license": "CC0 1.0",
     "license_url": "https://creativecommons.org/publicdomain/zero/1.0/",
     "description_on_source": "Recorded the air conditioner in our room while in Amman/Jordan last summer with HQ Recorder for iOS.",
     "freesound_id": "625224"
    }
   ],
   "diffio": {
    "model": "diffio-4.6-pro",
    "interface": "Diffio public API via the official Python SDK (diffio on PyPI)",
    "requested_at_utc": "2026-11-03T17:39:00Z",
    "download": "downloadType=audio (audio/mpeg); restored speech only, no background mixed back",
    "post_processing": "none except the loudness gain below"
   },
   "loudness_matching": {
    "standard": "ITU-R BS.1770-4 integrated loudness (pyloudnorm)",
    "target_lufs": -21.0,
    "before_lufs_raw": -20.74,
    "after_lufs_raw": -20.03,
    "before_gain_db": -0.26,
    "after_gain_db": -0.97,
    "note": "one static gain per file; no EQ, limiting, trimming or noise processing"
   },
   "files": {
    "original": "zoom-01-original.mp3",
    "restored": "zoom-01-restored.mp3"
   }
  }
 ]
}