# Airy transition whoosh

A sweep of air carries a scene cut, with a low layer giving it body.

Source checkpoint: 8dc3dd143f8eb56223e62d40c694689330a94853. Original procedural synthesis by Renaissance Solutions with Codex.
Local review candidate: public distribution and reuse terms have not yet been selected.
Numbered audio, source and presets are preserved unchanged. Listening preferences and use under narration remain pending.

## Make it with your AI assistant

Ask whether your assistant can run Python and return WAV files. Give it this complete folder (or upload this ZIP and ask it to extract the files).
No account keys or Python packages are needed by the recipe. Use the supplied generator to reproduce our takes.
A prompt alone can lead to a different implementation.

Help me make an original podcast sound effect:
an airy transition whoosh for a scene cut or slide change.
Let filtered air swell and settle while a quiet low body gives it weight.
Move gently from left to right. Avoid a sharp impact or recognizable sample.
Use a 0.70-second sweep inside a 1.20-second file, with a short lead-in.

Synthesize it with Python's standard library, with no external samples,
paid audio providers, voices, or downloaded assets. Separate the
air sweep and low body into aligned stereo stems.
Save a 48 kHz / 24-bit stereo master, mono fold-down, both 24-bit stems,
and a 16-bit stereo preview. Aim for -6 dBFS sample-peak headroom.

Save the complete source, fixed-seed JSON settings, tool versions,
measurements, and a SHA-256 manifest. Preserve the first take as v001.
If you can run the code, render the files and report the checks.
If you cannot, provide the code and commands and label execution pending.
Do not invent listening feedback or claim the effect is mix-ready.

## Run locally

Unzip the complete kit and open Terminal in the folder containing this README, effects/, scripts/ and library/.
Python 3.10 or later is required; reference bytes were generated with Python 3.14.3 on macOS.
Run the following commands from that folder. Use a fresh output folder for every attempt; existing takes will not be overwritten.

python3 effects/002-transition-whoosh/src/render.py --preset effects/002-transition-whoosh/presets/v001.json --output tmp/002-transition-whoosh-v001

python3 effects/002-transition-whoosh/src/render.py --preset effects/002-transition-whoosh/presets/v002.json --output tmp/002-transition-whoosh-v002

Open each new preview.wav in an audio player. stereo.wav is the 48 kHz/24-bit master, mono.wav is its mono fold-down, and stems/ contains aligned layers.
Check the retained files and reproduce all WAVs with:

python3 scripts/verify_library.py --reproduce

Byte equality is verified in the recorded runtime; check other runtimes. This command does not judge how a sound feels.

## What we did

1. Shape a noise texture into a rising and falling air sweep.
2. Add a soft low layer to give the movement weight.
3. Save both layers on the same timeline.

## Change one thing

Make a shorter version for a quicker scene cut.
Preserve v001. Copy its preset, change sweep_seconds from
0.70 to 0.40, and change only the take label to v002.
Keep the source, character label, seed, remaining settings, file length,
formats, and -6 dBFS sample-peak target fixed. Render a new take.
Return both mixes and stems, verify the exact preset difference, and
report the shared-gain and RMS differences. Leave preference undecided.

Use the supplied source for these parameter names. With newly written code, first identify the equivalent control.
The sweep changes from 0.70 to 0.40 seconds. The file length stays fixed, leaving more quiet space afterward.
Both mixes share a sample-peak target; that does not mean they seem equally loud.

## Listen and decide

Does the shorter sweep fit the cut, or end before the movement feels complete?
Place the whoosh at a slide change or between two spoken sections. Try it before and after the cut. Compare both takes and the passage without the effect.
Record what you heard, your preference (including neither or undecided), and one next change.
Technical checks passed for the reference files; human listening and use in context remain pending.

## Source identity

The original chapter SHA-256 is 1290039b0bd2ec31c0893f99591a8518d6b1fe6658cf728dab4606eef1798909.
Each library manifest records source, preset, dependencies and WAV hashes.
The included catalog is the matching single-recipe subset of the pinned Studio catalog.