# Defensive Publication — Non-Contact Control of Drumhead Resonance Decay by a Proximity Acoustical Resistor

**Author / inventor:** Calvin D. Rose · calvinrose18938@gmail.com
**Type:** Technical disclosure / defensive publication (non-patent literature)
**Status:** Version 1.0, for public release as a defensive publication. The authoritative public-disclosure date is the timestamp of the archived record (e.g., the Zenodo DOI) created when this is deposited — not any date printed in the files.

## Purpose

This repository is a **defensive publication**. The device and methods — conceived
by the author in the late 1970s, developed and measured, but **never patented and
never previously disclosed publicly** — are published here as enabling, dated,
public **prior art**, so they remain free for anyone to use and cannot be
monopolized by a later patent. The author does not seek a patent.

## What is disclosed

A method for shortening and tuning the decay time of a drumhead's resonant modes
— including selectively shortening the long-ringing overtones — using an
acoustically resistive material (porous/perforated foam, cloth, fiber, or metal)
held in **close proximity to, but not touching**, the drumhead. The oscillating
near-field air driven by the vibrating head is forced through the resistive
material, dissipating modal energy as heat; the geometry (ring inside diameter,
gap distance, coverage, orientation) selects which modes are damped. Because
nothing contacts the head, its strike response and feel are preserved. See
`whitepaper.pdf` for the principle, the family of embodiments (with the inventor's
original drawings), the measured demonstrations, and the enumerated variants.

## Contents

| Item | Description |
|------|-------------|
| `whitepaper.pdf` | The full technical disclosure (principle, embodiments, measured results, variants, original drawings, code appendix). |
| `whitepaper.tex` | LaTeX source. |
| `analyze.py` | Analysis code (numpy + scipy + matplotlib) reproducing every figure from the recordings. |
| `wav/` | The demonstration recordings (decoded), the measured evidence. |
| `fig1_spectrograms.png`, `fig2_decay_rt60.png`, `fig3_tunability.png` | Generated result figures. |
| `fig_ring/aperture/flue/perp/foam.png` | The inventor's original embodiment drawings (headers cropped). |
| `DISCLOSURE_METADATA.md` | Submission cover sheet: abstract, keywords, dates, venue checklist. |
| `CITATION.cff` | Machine-readable citation metadata. |
| `SHA256SUMS.txt` | Integrity hashes for timestamping. |
| `TIMESTAMP.md` | How to establish the disclosure date. |
| `LICENSE-PAPER-CC0-1.0.txt` / `LICENSE-CODE-Apache-2.0.txt` | Licenses. |

## Reproducing the results

```bash
pip install numpy scipy matplotlib
python3 analyze.py     # reads wav/, writes fig1/fig2/fig3
```

## Licensing

Document (paper, figures, this README): **CC0 1.0** (public domain). Code
(`analyze.py`): **Apache-2.0** (includes a patent grant). The demonstration
recordings in `wav/` are released under **CC0 1.0**. Authorship is retained as a
matter of record regardless of license.

## How to cite

> Calvin D. Rose. *Non-Contact Control of Drumhead Resonance Decay by a Proximity
> Acoustical Resistor.* Technical disclosure, 2026. (Add DOI/venue after deposit.)

See `DISCLOSURE_METADATA.md` for the deposit checklist.
