I don't have a car, by choice. My neighborhood has stores nearby and bus lines that make it perfect for walking or public transit. Ever since I can remember, I've loved to take long walks around my neighborhood and explore the world at a human pace. Portable audio was the perfect match! The side streets are quiet, with minimal car traffic. However, I still need to filter out the noise around me especially on buses, the metro and noisy sidewalks next to busy streets. Cranking up the volume is one option, but not healthy for ears that need to last a lifetime.
A few years ago, I discovered Koss Plug headphones that insert an expanding foam plug within the ear canal, like the safety earplugs I used when mowing lawns. The first time I tried them out, they fit perfectly into my ear and blotted out even the loudest noises. Rumbling city buses and poorly tuned cars no longer interrupted my news feeds, science articles and audiobooks.
The plugs performed well for the first five or six times, but changed their resilience over time. The slow recovery property or memory of the foam seemed to fade, so it became harder to position them inside my ear at the depth required to block sound. They seemed to lose springiness too. If I turned my head, one edge of the foam edge would deform and block the center channel, silencing one of my ears until the foam spring back. During winter, the edges of my hat or hood covering my ears would would have the same effect, tilting the plug inside my ear and blocking the channel. Plus, the plugs would eventually get dirty from earwax - yuck!
I remembered further back to a pair of silicone earplugs, EarPlanes, that worked much better than the foam safety earplugs. They were made from a hollow silicone tube with a cylindrical portion on one end and flanges at the other. The central channel had a ceramic element for equalizing air pressure. The directions suggest placing the flanges inside the ear canal, but they worked better by using the other tapered cylindrical end.
Maybe someone had already combined these ideas together. Jabra headsets come close, but don't place the silicone tube far enough in the ear. Other instructables teaches how to modify earplugs with the same expanding earplug foam as the Koss design.
Since the silicone material in EarPlanes doesn't compress, they wouldn't deform and close up when I turned my head or wore a hat. A search for silicone ear plugs turned up many designs for earbuds described as "in-ear," but they don't extend far enough into the ear to block sound adequately. Plus, it seems that my ears are smaller than most of the designs out there, so they keep falling out.
OK, enough yakking! Time to make earplugs!
remove ink tubes from pens
tape ink tubes to container
apply silicone to ink tubes
remove cured silicone tubes
trim silicone tubes