# Disclosure Cover Sheet & Deposit Checklist

Use this sheet when depositing. Copy the abstract/keywords into each venue's form.

## Bibliographic metadata

- **Title:** Non-Contact Control of Drumhead Resonance Decay by a Proximity Acoustical Resistor
- **Author / inventor:** Calvin D. Rose
- **Contact:** calvinrose18938@gmail.com
- **Document type:** Technical disclosure / defensive publication (non-patent literature)
- **Conceived:** late 1970s · **Never filed as a patent · never previously disclosed publicly**
- **Date of public disclosure:** _____________ (fill in at deposit; this is the prior-art date)
- **Document license:** CC0 1.0 (`SPDX: CC0-1.0`) · **Code license:** Apache-2.0 (`SPDX: Apache-2.0`)
- **DOI:** _____________ (assigned by Zenodo/preprint server after deposit)

## Abstract

A method for shortening and tuning the decay time of a drumhead's resonant modes
— including selectively shortening the overtones — using an acoustically
resistive element held in close proximity to, but not touching, the drumhead. A
porous or perforated material (open-cell foam, cloth, fiber, or perforated metal
or plastic) is positioned within a distance small compared with the wavelength of
the mode of interest. The oscillating near-field air motion driven by the
vibrating membrane is forced through the resistive material, where viscous and
thermal losses convert modal energy to heat, raising the modal damping and
shortening the decay time. Because the near field of a membrane mode has a spatial
extent set by its wavelength, the geometry and placement of the resistor — ring
inside diameter, gap distance, coverage, and orientation — select which modes are
damped, allowing the fundamental, the overtones, or both to be targeted, at a
fixed setting or continuously adjustable. Unlike contact mufflers, gels, rings,
and internal dampers, nothing touches or loads the vibrating surface. The
disclosure gives the physical principle, a family of embodiments with the
inventor's original drawings, and measured demonstrations (spectrograms, energy
decay, and RT60) confirming strong, tunable, contact-free decay control that meets
or exceeds a commercial contact muffler.

## Keywords

drum; drumhead; membrane damping; overtone control; acoustic resistance; porous
absorber; decay time; RT60; sustain control; non-contact muffling; percussion;
defensive publication; prior art.

## Deposit checklist (publish in several venues examiners search)

- [ ] **Zenodo** — deposit `whitepaper.pdf` + the full bundle zip; get a permanent DOI and timestamp. (Free.)
- [ ] **Preprint server** — TechRxiv or engrXiv/arXiv (physics.class-ph / eess.AS), for reach and Google Scholar indexing.
- [ ] **Prior Art Archive** (priorartarchive.org) — free; feeds Google Patents, which examiners search.
- [ ] **Technical Disclosure Commons** (tdcommons.org) — free, purpose-built defensive-publication venue.
- [ ] **(Optional, paid) IP.com or Research Disclosure** — distributed directly to patent offices worldwide.
- [ ] Verify the deposit is crawlable (no login wall) and appears in Google / Google Scholar / Google Patents.
- [ ] Record the timestamp proof (`SHA256SUMS.txt` + OpenTimestamps `.ots`, see `TIMESTAMP.md`) with the DOI.

## Integrity

```bash
sha256sum -c SHA256SUMS.txt
```
