# UI sounds — provenance

Aircraft-themed UI sounds played by `public/assets/js/sound-effects.js` (`window.ABCSounds`).

Every file here is an edit of a recording published on [Freesound](https://freesound.org)
under **[CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/)** (public domain — no
attribution required). The authors are listed anyway so the origin of each file can always
be traced. Licence checked on each sound's page on 2026-09-21.

| File | Source | Author | What it is |
|---|---|---|---|
| `chime_ding.mp3` | [197248](https://freesound.org/people/qubodup/sounds/197248/) | qubodup | Fasten-seatbelt signal recorded in a cabin — first ding |
| `chime_double.mp3` | [197248](https://freesound.org/people/qubodup/sounds/197248/) | qubodup | Same recording — both dings |
| `chime_ding-soft.mp3` | [88787](https://freesound.org/people/Josh%20Herman/sounds/88787/) | Josh Herman | Flight-attendant call-button ding |
| `chime_hi-lo.mp3` | [245851](https://freesound.org/people/Shamrock132/sounds/245851/) | Shamrock132 | Airbus A320 interphone chime — hi and lo notes |
| `chime_lo.mp3` | [245851](https://freesound.org/people/Shamrock132/sounds/245851/) | Shamrock132 | Same recording — lo note only |
| `chime_tritone.mp3` | [244583](https://freesound.org/people/nachosose/sounds/244583/) | nachosose | Airbus A320 tri-tone PA chime |
| `click_handset.wav` | [245851](https://freesound.org/people/Shamrock132/sounds/245851/) | Shamrock132 | A320 interphone handset being hung up |
| `click_buckle-in.wav` | [418199](https://freesound.org/people/ddaedalus/sounds/418199/) | ddaedalus | Airplane seatbelt buckle fastening |
| `click_switch-01.wav` … `-03.wav`, `click_release.wav` | [442353](https://freesound.org/people/toddcircle/sounds/442353/) | toddcircle | Locking push-button — presses and one release |
| `click_switch-04.wav` | [690300](https://freesound.org/people/Ralph0o7/sounds/690300/) | Ralph0o7 | Push-button switch click |
| `click_toggle-on.wav`, `click_toggle-off.wav` | [413851](https://freesound.org/people/jaegrover/sounds/413851/) | jaegrover | Two-element toggle switch, on and off |
| `click_latch.wav` | [815493](https://freesound.org/people/xkeril/sounds/815493/) | xkeril | Mechanical latch |

**Edits made** (with `sox`, from Freesound's HQ MP3 previews): downmixed to mono at
44.1 kHz; each event cut out of its recording; high-pass filtered to remove cabin rumble
(120–250 Hz on chimes, 800 Hz on the buckle); faded out; peak-normalised (chimes −6 dB,
clicks −12 dB). In `chime_hi-lo`, `chime_double` and `chime_tritone` the gaps between notes
were shortened from ~1 s to ~0.5 s so they work as UI feedback — the notes themselves are
unaltered. Nothing is synthesized or pitch-shifted. Chimes are 96 kbps MP3; clicks are
16-bit WAV, because MP3 encoder padding would delay a 0.2 s click noticeably.

The switch, toggle and latch clicks are ordinary mechanical switches, not aircraft parts —
no CC0 recording of real cockpit switches was available. The chimes, the handset and the
buckle are genuine aircraft recordings.

The dashboard's `public/assets/audio/airbus-cabin.mp3` predates this set and is not part of it.