# Street Heat audio sources and licenses

Retrieved and verified 2026-09-09. These are downloaded authored/recorded sound assets, not generated oscillator placeholders. Original nongun files are retained without audio changes in this directory. Original firearm files are retained in game/art-source/audio, excluded from deployment; compact derivatives are delivered here. Runtime trimming, crossfading, pitch variation, filtering, mixing, and gain changes should be identified in credits for the CC BY engine recording.

## Required credit for engine-driving-kurt.ogg

“Engine Sound” by kurt — https://opengameart.org/content/engine-sound — licensed under Creative Commons Attribution3.0 Unported, https://creativecommons.org/licenses/by/3.0/. Used in Street Heat with runtime looping/crossfading, pitch, gain, and filtering adaptations.

The original author says the recording was captured while driving. Commercial use and adaptations are permitted under CC BY3.0 provided appropriate attribution and license link are supplied. This credit must appear in the game's accessible credits; preserving this file alone is not the intended user-facing credit implementation.

## Complete provenance

| File | Author/source work | License | Original download |
| --- | --- | --- | --- |
| engine-driving-kurt.ogg | kurt, Engine Sound, https://opengameart.org/content/engine-sound | CC BY3.0, mandatory credit above | https://opengameart.org/sites/default/files/enginehum3.ogg |
| engine-start.wav | looneybits, Car engine start01, https://opengameart.org/content/car-engine-start-01 | CC0 1.0 | https://opengameart.org/sites/default/files/generic_car_startengine.wav |
| explosion-tail.wav | NenadSimic, Muffled Distant Explosion, https://opengameart.org/content/muffled-distant-explosion | CC0 1.0 | https://opengameart.org/sites/default/files/NenadSimic%20-%20Muffled%20Distant%20Explosion.wav |
| explosion-chunky.mp3 | Joth, Chunky Explosion, https://opengameart.org/content/chunky-explosion | CC0 1.0 | https://opengameart.org/sites/default/files/Chunky%20Explosion.mp3 |
| impact-metal-heavy.ogg | Kenney, Impact Sounds1.0, archive Audio/impactMetal_heavy_000.ogg, https://kenney.nl/assets/impact-sounds | CC0 1.0; original KENNEY-LICENSE.txt included | https://kenney.nl/media/pages/assets/impact-sounds/87b4ddecda-1677589768/kenney_impact-sounds.zip |
| impact-metal-light.ogg | Kenney, Impact Sounds1.0, archive Audio/impactMetal_light_002.ogg | CC0 1.0 | Same Kenney archive |
| gun-ak47.wav | Ben Jaszczak, Brian Nelson, Kevin Heras, Matthew Nanney, The Free Firearm Sound Library; archive AK-47/C_27P.wav | CC0 1.0 | https://opengameart.org/sites/default/files/Prepared%20SFX%20Library.7z |
| gun-ar15.wav | Same firearm team; archive AR-15/D_24P.wav | CC0 1.0 | Same firearm archive |

CC0 license: https://creativecommons.org/publicdomain/zero/1.0/ . Attribution is optional for CC0 files; the author names above are retained as provenance.

Firearm primary-source license verified in the authors' archived homepage: https://web.archive.org/web/20141217041948/http://freefirearmsfx.com/ . Their statement explicitly permits personal/professional application without royalty or credit. Public archive mirror and team identification: https://opengameart.org/node/21826 . Large firearm archive remains in ignored local temporary storage; only two selected WAVs are included here. The noisy Tabasco collection was researched but not downloaded or selected.

## Technical checks and integration limits

Browser AudioContext decoded all8 sources successfully at48kHz stereo. Engine23.596s, start1.647s, chunky explosion5.616s, explosion tail5.143s, metal heavy0.165s, metal light0.233s. Engine and impacts/explosions have no decoded samples at full scale. Gun rawfiles contain two isolated shots with long gaps: AK9.939s and AR6.485s; do not play fullfiles for every rapidfire shot. Slice the first shot and its shorttail (roughly first2s AK or1.4s AR), lower gain, and manage voice count. Decoded gun peaks exceed1 slightly after sample-rate conversion (1.065/1.092), so preserve headroom or normalize to≤0.8peak before mixing. No subjective listening-quality acceptance is claimed by this source/download audit. Mix audition is still required.

The explosion tail is a recorded log-drum hit with delayed reverberation, not an actual explosive event. Joth describes the chunky explosion as pseudorealistic. These authored layers improve transient/tail texture but must be judged in the final mix. Enginehum is a driving ambience recording; source is not promised sample-perfect seamless. Select a steady region and crossfade.

Integration agent reports engine loop uses original8–15s region with350ms crossfade, playback-rate pitch and lowpass/gain treatment. Guns use a short first320ms attack slice with50ms fade and conservative gain/limiter; attack-onset timing still must be checked before accepting that slice. These changes happen in runtime buffers; downloaded sourcefiles remain unmodified.


## Compact firearm runtime exports

`gun-ak47-short.wav` and `gun-ar15-short.wav` are0.55s mono44.1kHz PCM16 derivatives,48,554bytes each. AK source attack begins0.271224s, export starts0.265224s; AR attack begins0.549252s, export starts0.543252s. Both exports position attack at6ms, fixing the otherwise silent first320ms AR slice. Stereo downmixed, gain0.8AK/0.774071AR to preserve≤0.8peak,2ms fadein and50ms fadeout. Original gun files moved to game/art-source/audio (excludeddeploy); source license and original archive provenance above apply unchanged.

## Pursuit and tire loops added 2026-09-09

- siren-wail-loop.wav: conleec, Police Siren Wailer Static, https://freesound.org/people/conleec/sounds/159753/, CC0. Published HQ MP3 preview used. Original 1–9 second section, mono 22.05kHz PCM16, 250ms overlap crossfade, final 7.75 seconds. Runtime proximity, pan, restrained Doppler playback-rate adjustment, gain and lowpass filtering.
- rotor-loop.wav: aquinn, Helicopter Sounds, https://opengameart.org/content/helicopter-sounds/, CC0. Original 0.2–3.7 second section, mono 22.05kHz PCM16, 200ms overlap crossfade, final 3.3 seconds. Runtime aircraft proximity, pan, type-specific pitch and lowpass filtering. Source metadata does not establish field-recording provenance.
- tire-squeal-loop.wav: Tom Haigh (audible-edge), loop edit qubodup, Car Tire Squeal / Skid Loop, https://opengameart.org/content/car-tire-squeal-skid-loop, CC BY3.0 https://creativecommons.org/licenses/by/3.0/. Downmixed/resampled to mono 22.05kHz PCM16, normalized to ≤0.8 peak, 150ms overlap crossfade, final 2.85 seconds; runtime filtering, gain, and pitch treatment. Audible under hard braking or high-speed steering load. Original source https://freesound.org/people/audible-edge/sounds/71739/. Required derivative credit appears in accessible game credits.

These three derivatives total 613,124 bytes. Waveform/decode checks do not establish subjective listening acceptance.


## Optional streamed music

../music-signal-pursuit.mp3: Vitalezzz, Signal Pursuit, https://opengameart.org/content/signal-pursuit, CC0 1.0 https://creativecommons.org/publicdomain/zero/1.0/. Source MP3 retained unchanged, streamed by HTMLAudioElement through the game master bus rather than decoded into an AudioBuffer. Runtime level, action ducking, pause/resume, and optional music toggle. Source described as an electronic arcade soundtrack; subjective listening acceptance is not asserted by implementation tests.