Sources and licenses for the /fix-zoom-audio/ sample
Prepared November 3, 2026. The "original" is a simulated video call built from the sources below; the "restored"
file is Diffio 4.6 Pro's restored speech from the Diffio API on November 3, 2026, with no background mixed in.
Both files have one fixed gain so they play at about the same loudness. No other processing. Details: manifest.json.
None of the people or organizations below are Diffio customers or endorse Diffio.

zoom-01 (zoom-01-original.mp3, zoom-01-restored.mp3)
Caption: 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.

1. Speech: LibriTTS test-clean, speaker 6829, utterances 6829_68769_000056_000001 to _000007
   LibriTTS (Zen et al., 2019), from a public domain LibriVox reading. https://www.openslr.org/60/
   License: CC BY 4.0, https://creativecommons.org/licenses/by/4.0/
   Changes: sentences joined with short silences, shaped with a laptop-microphone EQ, convolved with the room
   impulse response, mixed with the noise, encoded and decoded with Opus at 6 kbps with simulated packet loss.

2. Room impulse response: BUT Speech@FIT Reverb Database, room R112 (hotel room, about 40 cubic meters)
   Brno University of Technology, Speech@FIT (Szöke et al., 2019).
   https://speech.fit.vut.cz/software/but-speech-fit-reverb-database
   License: CC BY 4.0, https://creativecommons.org/licenses/by/4.0/
   Changes: truncated to 1 s with a 50 ms fade-out and aligned to the direct-path peak.

3. Noise: "Air Conditioner" by sonically_sound, Freesound.
   https://freesound.org/people/sonically_sound/sounds/625224/
   License: CC0 1.0, https://creativecommons.org/publicdomain/zero/1.0/ (credited as a courtesy)