# Ghoul Ball audio credits

Every file here is a real recording (no synthesized sounds) under a license that allows use in a free public game: CC0, CC-BY 3.0/4.0, or Kenney (CC0). There is no NC, SA, ripped or unclear-license material.

**Processing applied to all effects** (unless noted): we cut a single clean hit from the source (with a 2 ms fade-in and a short fade-out), removed DC offset, downmixed to mono, normalized the peak to about -1 dBFS and encoded to 96 kbps MP3 with ffmpeg/libmp3lame. Rolling loops are 16-bit 22.05 kHz mono WAV, crossfaded so they loop seamlessly. They are WAV because MP3 encoder padding puts a gap in loops on Safari. Freesound sources were downloaded as Freesound's HQ preview MP3s.

Gain varies: flipper_down is about 13 dB quieter than flipper_up in the source and was normalized up, so play it at a lower volume. The roll loops came from quiet recordings (+23 to +31 dB of gain), so expect a little room noise.

## Attribution line (for the game's credits screen)

Sounds from Freesound.org: "pinball" by kirkm (CC BY 4.0); "Button click microswitch" by michaelkoehler (CC BY 4.0); "Marble, Rolling on Wood, A.wav" by InspectorJ (www.jshaw.co.uk) of Freesound.org (CC BY 4.0); "Metal ball_rolling on curtain rods.wav" by rubberduckie (CC BY 4.0); "Newtons Cradle 2" by LoafDV (CC BY 4.0); "Piano lid slamming.wav" by NEDDYBLOWER (CC BY 3.0). The other sounds are CC0, by schafferdavid, relwin, bassmosphere, CHallSmith, shdwtek, jhka, jodybruchon, Hallkom, NeatoEnt, drewtait, datsinoil, magnuswaker, qubodup, fractionalist and northern87 (Freesound), plus Kenney (kenney.nl). Music: "Exhilarate" and "Surf Shimmy" by Kevin MacLeod (incompetech.com), licensed under Creative Commons: By Attribution 4.0 License, http://creativecommons.org/licenses/by/4.0/. "Halloween Rock'n'Roll" by PlayOnLoop.com, CC BY 3.0.

## Effects

| File | What it is | Real pinball? | Source URL | Author | License | Changes |
|---|---|---|---|---|---|---|
| bumper_1.mp3 | Pop bumper hit, 1977 Gottlieb Bronco | Yes | https://freesound.org/people/schafferdavid/sounds/450265/ | schafferdavid | CC0 | Cut 3.499–3.930 s, normalized |
| bumper_2.mp3 | Pop bumper hit, 1977 Gottlieb Bronco | Yes | https://freesound.org/people/schafferdavid/sounds/450265/ | schafferdavid | CC0 | Cut 1.154–1.445 s, normalized |
| bumper_3.mp3 | Pop bumper hit, 1963 Gottlieb Slick Chick (EM, brighter) | Yes | https://freesound.org/people/relwin/sounds/172275/ | relwin | CC0 | Cut 0.117–0.340 s, normalized |
| flipper_up_1..3.mp3 | Flipper energizing (flip up), 1977 Gottlieb Bronco | Yes | https://freesound.org/people/schafferdavid/sounds/450270/ | schafferdavid | CC0 | Cuts 3.230–3.478, 5.320–5.532, 6.744–7.032 s, normalized |
| flipper_down_1..3.mp3 | Flipper release (falls back), same recording | Yes | https://freesound.org/people/schafferdavid/sounds/450270/ | schafferdavid | CC0 | Cuts 3.482–3.800, 5.535–5.850, 7.035–7.320 s, normalized (+13 dB) |
| sling_1.mp3 | Large electrical relay slamming shut (solenoid-style clack) | No, stand-in | https://freesound.org/people/CHallSmith/sounds/870770/ | CHallSmith | CC0 | Cut 3.655–4.100 s, normalized |
| sling_2.mp3 | Solenoid hit from the Bronco bumper-area recording, used as a sling | Yes (machine), role assumed | https://freesound.org/people/schafferdavid/sounds/450265/ | schafferdavid | CC0 | Cut 2.359–2.800 s, normalized |
| knocker_1.mp3 | Knocker fired by hand, 1970s Bally (Hi-Lo Ace pack) | Yes | https://freesound.org/people/bassmosphere/sounds/384701/ | bassmosphere | CC0 | Cut 0.047–0.255 s (first strike), normalized |
| knocker_2.mp3 | Same knocker, second strike | Yes | https://freesound.org/people/bassmosphere/sounds/384701/ | bassmosphere | CC0 | Cut 0.255–0.580 s, normalized |
| kicker_1.mp3 | 12 V solenoid firing | No, stand-in (real solenoid) | https://freesound.org/people/shdwtek/sounds/679204/ | shdwtek | CC0 | Cut 1.010–1.250 s, normalized |
| kicker_2.mp3 | Very large relay closing (heavy clunk) | No, stand-in | https://freesound.org/people/CHallSmith/sounds/870770/ | CHallSmith | CC0 | Cut 8.880–9.300 s, normalized |
| drop_target_1.mp3 | Light generic impact (plastic-ish tock) | No, stand-in | https://kenney.nl/assets/impact-sounds (impactGeneric_light_001.ogg) | Kenney | CC0 | Whole file, mono, normalized |
| drop_target_2.mp3 | Wooden plank impact (drop thunk) | No, stand-in | https://kenney.nl/assets/impact-sounds (impactPlank_medium_000.ogg) | Kenney | CC0 | First 0.45 s, normalized |
| rollover_1.mp3 | Microswitch click (press) | No, stand-in (real microswitch) | https://freesound.org/people/michaelkoehler/sounds/219015/ | michaelkoehler | CC BY 4.0 | Cut 0.051–0.190 s, normalized |
| rollover_2.mp3 | Relay switch click from a 1970s pinball machine | Yes | https://freesound.org/people/bassmosphere/sounds/384698/ | bassmosphere | CC0 | Cut 0.052–0.190 s, normalized |
| spinner_1.mp3 | Ratchet spun once (revolver-chamber style), fast clicks | No, stand-in | https://freesound.org/people/jhka/sounds/139001/ | jhka | CC0 | Cut 0.027–0.780 s, normalized. The author sped the recording up 150%. |
| spinner_2.mp3 | Bicycle rear-hub ratchet clicking (slower spin) | No, stand-in | https://freesound.org/people/jodybruchon/sounds/459463/ | jodybruchon | CC0 | Cut 0.65–2.25 s, 300 ms fade-out, normalized |
| plunger_pull_1.mp3 | Steel spring being pulled (first pull) | No, stand-in | https://freesound.org/people/Hallkom/sounds/609524/ | Hallkom | CC0 | Cut 0.571–1.450 s, normalized |
| plunger_pull_2.mp3 | Same spring, second pull | No, stand-in | https://freesound.org/people/Hallkom/sounds/609524/ | Hallkom | CC0 | Cut 3.595–4.600 s, normalized |
| plunger_release_1.mp3 | Ball launched by plunger and rolling up the shooter lane, 1977 Gottlieb Bronco | Yes | https://freesound.org/people/schafferdavid/sounds/450267/ | schafferdavid | CC0 | Cut 1.396–2.750 s, 400 ms fade-out, normalized |
| plunger_release_2.mp3 | Ball launched into the playfield, 1970s Bally Hi-Lo Ace | Yes | https://freesound.org/people/bassmosphere/sounds/384702/ | bassmosphere | CC0 | Cut 0.145–0.800 s, normalized |
| trough_1.mp3 | Ball falling down past the flippers (drain), 1977 Gottlieb Bronco | Yes | https://freesound.org/people/schafferdavid/sounds/450266/ | schafferdavid | CC0 | Cut 0.685–1.400 s, normalized |
| trough_2.mp3 | Ball dropping into the outhole at the end of a drain, 1970s Bally | Yes | https://freesound.org/people/bassmosphere/sounds/384702/ | bassmosphere | CC0 | Cut 2.942–3.490 s, normalized |
| trough_3.mp3 | Second drain event in the Bronco recording (ball landing below the flippers) | Yes | https://freesound.org/people/schafferdavid/sounds/450266/ | schafferdavid | CC0 | Cut 2.577–3.350 s, normalized |
| roll_loop_1.wav | Marble rolling on a hard table, recorded for a pinball game | No, stand-in | https://freesound.org/people/NeatoEnt/sounds/458137/ | NeatoEnt | CC0 | 37.0–42.0 s, 250 ms crossfade loop, normalized (+23 dB), 22.05 kHz WAV |
| roll_loop_2.wav | Glass marble rolling on a wooden floor | No, stand-in | https://freesound.org/people/InspectorJ/sounds/429104/ | InspectorJ | CC BY 4.0 | 1.0–4.4 s, 250 ms crossfade loop, normalized, 22.05 kHz WAV |
| roll_metal_loop_1.wav | Metal ball rolling on metal curtain rods | No, stand-in | https://freesound.org/people/rubberduckie/sounds/639646/ | rubberduckie | CC BY 4.0 | Spliced 67.70–69.12 + 69.32–70.78 s (40 ms crossfades, looped), normalized (+31 dB), 22.05 kHz WAV |
| roll_metal_loop_2.wav | Same, another stretch | No, stand-in | https://freesound.org/people/rubberduckie/sounds/639646/ | rubberduckie | CC BY 4.0 | Spliced 141.40–142.45 + 142.85–143.95 s, looped, normalized (+31 dB), 22.05 kHz WAV |
| hit_wood_1.mp3 | Marble dropped on a hard table (single bounce) | No, stand-in | https://freesound.org/people/NeatoEnt/sounds/458137/ | NeatoEnt | CC0 | Cut 67.101–67.235 s, normalized |
| hit_wood_2.mp3 | Light wood impact | No, stand-in | https://kenney.nl/assets/impact-sounds (impactWood_light_000.ogg) | Kenney | CC0 | Whole file, normalized |
| hit_wood_3.mp3 | Marble bounce on a hard table, short | No, stand-in | https://freesound.org/people/NeatoEnt/sounds/458137/ | NeatoEnt | CC0 | Cut 50.283–50.360 s, normalized |
| hit_metal_1.mp3 | Light metal impact | No, stand-in | https://kenney.nl/assets/impact-sounds (impactMetal_light_001.ogg) | Kenney | CC0 | Whole file, normalized |
| hit_metal_2.mp3 | Light metal impact, longer ring | No, stand-in | https://kenney.nl/assets/impact-sounds (impactMetal_light_003.ogg) | Kenney | CC0 | Whole file, normalized |
| hit_rubber_1.mp3 | Large gym rubber band, plucked thud | No, stand-in | https://freesound.org/people/datsinoil/sounds/689246/ | datsinoil | CC0 | Cut 0.006–0.550 s, normalized |
| hit_rubber_2.mp3 | Soft, dull impact | No, stand-in | https://kenney.nl/assets/impact-sounds (impactSoft_medium_001.ogg) | Kenney | CC0 | Whole file, normalized |
| ball_click_1.mp3 | Steel balls clacking (Newton's cradle, one click) | No, stand-in (steel balls) | https://freesound.org/people/drewtait/sounds/676377/ | drewtait | CC0 | Cut 2.119–2.230 s, normalized |
| ball_click_2.mp3 | Newton's cradle, one click | No, stand-in (steel balls) | https://freesound.org/people/LoafDV/sounds/131596/ | LoafDV | CC BY 4.0 | Cut 0.305–0.450 s, normalized |
| chime_lo_1.mp3 | EM chime unit, low chime (~317/628 Hz), 1970s Sonic machine with a Williams chime unit | Yes | https://freesound.org/people/kirkm/sounds/840401/ | kirkm | CC BY 4.0 | Cut 4.125–4.800 s, normalized |
| chime_mid_1.mp3 | Same chime unit, middle chime (~770 Hz) | Yes | https://freesound.org/people/kirkm/sounds/840401/ | kirkm | CC BY 4.0 | Cut 5.165–6.150 s, normalized |
| chime_hi_1.mp3 | Same chime unit, high chime (~953 Hz) | Yes | https://freesound.org/people/kirkm/sounds/840401/ | kirkm | CC BY 4.0 | Cut 7.415–8.380 s, normalized |
| chime_lo_2.mp3 | Score bell/chime (~645 Hz), 1973 Bally Nip-It | Yes | https://freesound.org/people/relwin/sounds/172266/ | relwin | CC0 | Cut 2.405–3.280 s, normalized |
| chime_mid_2.mp3 | Score bell/chime (~785 Hz), 1973 Bally Nip-It | Yes | https://freesound.org/people/relwin/sounds/172266/ | relwin | CC0 | Cut 3.985–4.800 s, normalized |
| chime_hi_2.mp3 | Score bell/chime (~996 Hz), 1973 Bally Nip-It | Yes | https://freesound.org/people/relwin/sounds/172266/ | relwin | CC0 | Cut 5.395–5.950 s, normalized |
| crunch_1.mp3 | Heavy metal panels smashing plus breaking glass (car-crash style) | No (real metal and glass) | https://freesound.org/people/magnuswaker/sounds/592388/ | magnuswaker | CC0 | First 2.1 s, 400 ms fade-out, normalized. The author time-stretched the original. |
| crunch_2.mp3 | Short car-crash clank | No | https://freesound.org/people/qubodup/sounds/151624/ | qubodup | CC0 | Whole file, normalized. The author built it from a real recording (sagetyrtle) plus added noise. |
| chomp_1.mp3 | Steel spring bear trap clamping shut | No (real trap) | https://freesound.org/people/fractionalist/sounds/644245/ | fractionalist | CC0 | Cut 0.791–1.900 s, normalized |
| chomp_2.mp3 | Piano lid slammed (with string echo) | No (real lid) | https://freesound.org/people/NEDDYBLOWER/sounds/110972/ | NEDDYBLOWER | CC BY 3.0 | Cut 0.018–1.000 s, normalized |
| chomp_3.mp3 | Chest lid closed hard | No (real lid) | https://freesound.org/people/northern87/sounds/369988/ | northern87 | CC0 | Cut 0.150–0.700 s, normalized |

## Music

| File | What it is | Source URL | Author | License | Changes |
|---|---|---|---|---|---|
| music_1.mp3 | "Exhilarate": 170 bpm aggressive, driving instrumental rock (guitar, bass, drum kit, synth), 2:25 | https://incompetech.com/music/royalty-free/index.html?isrc=USUAN1300028 | Kevin MacLeod (incompetech.com) | CC BY 4.0 | Re-encoded 320 → 112 kbps stereo, -4 dB to sit closer to the other tracks |
| music_2.mp3 | "Surf Shimmy": 170 bpm surf rock (guitar, bass, drums, organ), 2:03 | https://incompetech.com/music/royalty-free/index.html?isrc=USUAN1700018 (also https://incompetech.filmmusic.io/song/4448-surf-shimmy/) | Kevin MacLeod (incompetech.com) | CC BY 4.0 | Re-encoded 256 → 112 kbps stereo |
| music_3.wav | "Halloween Rock'n'Roll": retro 60s-TV-style Halloween rock loop with guitars, drums, organ, bells and theremin, 13.7 s loop | https://opengameart.org/content/halloween-rocknroll-music-loop | PlayOnLoop.com | CC BY 3.0 (credit link to Playonloop.com requested) | Unmodified original file. It is 8-bit 22 kHz stereo WAV, so it is lo-fi with some hiss. Kept as WAV so the loop has no gap. |