Audio samples on https://diffio.ai/remove-hum-hiss-static/

Each "original" is the clip uploaded to Diffio. Each "pro" file is the unedited restored speech that the
Diffio API returned with Diffio 4.6 Pro on November 3, 2026, with no background mixed back in. The only change to
either file is one fixed gain so both sides of a pair play at the same integrated loudness. The restored files
are adaptations of their sources and carry the same license.

[hiss-01]
Sample made by mixing clean speech (LibriTTS, CC BY 4.0) with a real recording of blank cassette tape hiss ("TAPE HISS Sonab c500 B" by foad, Freesound, CC0; high-passed at 1.5 kHz to drop the deck's low rumble). Restored with Diffio 4.6 Pro. Both clips are loudness-matched for playback.
- clean speech: LibriTTS test-clean speaker 237, utterances 237_126133_000033_000000 to 237_126133_000033_000001, LibriTTS (Zen et al., 2019), from a public-domain LibriVox reading. https://www.openslr.org/60/ (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/)
- impairment recording: TAPE HISS Sonab c500 B, foad. https://freesound.org/people/foad/sounds/443339/ (CC0 1.0, https://creativecommons.org/publicdomain/zero/1.0/)
Files: hiss-01-original.mp3, hiss-01-pro.mp3

[crackle-01]
Sample made by mixing clean speech (LibriTTS, CC BY 4.0) with a real recording of the crackle of a blank 1940s 78 rpm record groove ("78 surface noise.wav" by nervousneal, Freesound, CC0). Restored with Diffio 4.6 Pro. Both clips are loudness-matched for playback.
- clean speech: LibriTTS test-clean speaker 260, utterances 260_123288_000038_000000 to 260_123288_000038_000001, LibriTTS (Zen et al., 2019), from a public-domain LibriVox reading. https://www.openslr.org/60/ (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/)
- impairment recording: 78 surface noise.wav, nervousneal. https://freesound.org/people/nervousneal/sounds/341761/ (CC0 1.0, https://creativecommons.org/publicdomain/zero/1.0/)
Files: crackle-01-original.mp3, crackle-01-pro.mp3

[hum-60hz-01]
Sample made by mixing clean speech (LibriTTS, CC BY 4.0) with a real recording of 60 Hz ground-loop hum from a vintage boom box ("Analog Ground Loop Hum Noise" by grantorino551, Freesound, CC0). Restored with Diffio 4.6 Pro. Both clips are loudness-matched for playback.
- clean speech: LibriTTS test-clean speaker 1320, utterances 1320_122612_000039_000003 to 1320_122612_000039_000004, LibriTTS (Zen et al., 2019), from a public-domain LibriVox reading. https://www.openslr.org/60/ (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/)
- impairment recording: Analog Ground Loop Hum Noise, grantorino551. https://freesound.org/people/grantorino551/sounds/845049/ (CC0 1.0, https://creativecommons.org/publicdomain/zero/1.0/)
Files: hum-60hz-01-original.mp3, hum-60hz-01-pro.mp3