# Original fade listening examples

Created by Saturalabs on October 23, 2026. These are original synthetic test
tones, not recorded voices, musical performances, or AI separation results.

Each WAV contains 144,000 frames: three seconds of mono audio at 48,000 Hz,
stored as 16-bit little-endian PCM. Each file is 288,044 bytes, including its
basic 44-byte WAV header.

## Source and processing

The source is a 330 Hz cosine. Each source sample is generated as
`round(8192 × cos(2π × 330 × frame / 48000)) / 32768`.
The recording deliberately begins and ends at a nonzero level, making its
entrance and ending useful for an edge-fade comparison. Its sample peak is
0.25 (approximately −12.04 dBFS).

The website's `lib/audio/fade.ts` processor generates all three files:

- `original.wav`: fade in 0, fade out 0.
- `short-edges.wav`: fade in 0.005 seconds, fade out 0.005 seconds.
- `long-edges.wav`: fade in 0.5 seconds, fade out 1 second.

Enabled fades are linear in amplitude across their stored frames, including
exact zero and unity endpoints. Both processed files retain the source's full
frame count, unaffected middle samples, and maximum sample peak. Equal peaks
do not establish equal perceived loudness. Playback also depends on the player,
device level, audio routing, and your listening conditions.

Regenerate from the project root with:

```sh
node --import tsx scripts/generate-fade-examples.ts
```

The generator uses no downloaded audio, API, or AI inference. The public tool
decodes a selected original file locally before applying its fades. To reproduce
these settings yourself, download `original.wav`, select it in the fade tool,
and prepare each comparison from that original.

## Reuse

To the extent possible under law, Saturalabs dedicates these three original
WAV learning assets to the public domain under CC0 1.0 Universal:
https://creativecommons.org/publicdomain/zero/1.0/

You may reuse these examples without attribution. This dedication applies to
these three WAV assets, not to unrelated user recordings, software, trademarks,
or other website content.