{
  "page": "https://diffio.ai/make-audio-sound-better/",
  "samples": [
    {
      "id": "general-02",
      "type": "synthetic",
      "label": "Sample made from clean speech (LibriTTS, CC BY 4.0), dulled with a 3.5 kHz low-pass filter, played through a real measured lecture-room impulse response (BUT Speech@FIT Reverb Database, CC BY 4.0), mixed with a real cafe recording (by mikemoons, Freesound, CC0) and saved 30 dB below full scale. Both sides are loudness-matched for playback, so the low recording level is not audible here. Restored with Diffio 4.6 Pro. Both clips are loudness-matched for playback.",
      "claimableImpairments": [
        "distant microphone",
        "crowd/background voices",
        "reverb/echo",
        "muffled voice"
      ],
      "verification": "clef-omni and signal checks",
      "durationSeconds": 23.21,
      "files": {
        "original": "general-02-original.mp3",
        "pro": "general-02-pro.mp3"
      },
      "sources": [
        {
          "role": "clean speech",
          "title": "LibriTTS test-clean speaker 4077, utterances 4077_13751_000023_000000 to 4077_13751_000023_000005",
          "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/"
        },
        {
          "role": "room impulse response",
          "title": "BUT Speech@FIT Reverb Database, room D105 (lecture room, about 2,000 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/"
        },
        {
          "role": "impairment recording",
          "title": "cafe ambience",
          "author": "mikemoons",
          "url": "https://freesound.org/people/mikemoons/sounds/579500/",
          "license": "CC0 1.0",
          "license_url": "https://creativecommons.org/publicdomain/zero/1.0/"
        }
      ],
      "mixing": {
        "id": "general-02",
        "page": "make-audio-sound-better",
        "speech": "libritts_4077_13751_000023",
        "speech_eq": [
          [
            "lp",
            3500,
            2
          ]
        ],
        "ir": [
          "vut_fit_d105",
          "44e04fe55c630cfc.flac"
        ],
        "final_peak_dbfs": -30.0,
        "seed": 27,
        "steps": [
          {
            "speech_eq": [
              [
                "lp",
                3500,
                2
              ]
            ]
          },
          {
            "convolve_ir": "vut_fit_d105/44e04fe55c630cfc.flac",
            "ir_len_s": 0.877,
            "ir_tail_fade_s": 0.05
          },
          {
            "add_noise": [
              {
                "freesound_id": "579500",
                "snr_db": 8.0,
                "gain": 8.69674,
                "looped": false,
                "offset_s": 0.249
              }
            ]
          },
          {
            "final_peak_normalise_dbfs": -30.0
          }
        ],
        "sample_rate": 48000,
        "lead_s": 0.6,
        "tail_silence_s": 0.8,
        "duration_s": 23.18
      },
      "diffio": {
        "model": "diffio-4.6-pro",
        "generationId": "01f3a6b7-bded-4585-bc20-e3ce72f9015e",
        "requested_at_utc": "2026-11-03T17:44:05Z"
      },
      "loudnessMatching": {
        "standard": "ITU-R BS.1770-4 integrated loudness (pyloudnorm)",
        "target_lufs": -21.0,
        "before_lufs_raw": -49.94,
        "after_lufs_raw": -20.47,
        "before_gain_db": 28.94,
        "after_gain_db": -0.53,
        "note": "one static gain per file; no EQ, limiting, trimming or noise processing"
      }
    }
  ]
}