Doppler Labs is a start up making products that enhance how we experience sound while, at the same time, protecting our hearing. Early in their inception, they approached me about helping them to visualize the look-and-feel of their flagship product, the DUBS Acoustic Filters - a product geared towards concert goers and musicians that filters out sounds at harmful decibels, but still allows you to hear a friend talking next to you with clarity. Something you don't get from a standard earplug. Having had grown up playing drums, I immediately saw the value in such a concept and was excited to be a part of this. 
At the time of this quick project, DUBS was an idea in its infancy with a technology to back it up. Nothing had been developed as to the architecture of the product and the right ergonomic layout to fit in a user's ear. I had to make several assumptions in creating these concepts. For example, I assumed the ear bud would likely be either urethane foam or silicone and angle off of the exterior face into the ear canal. Below are some of these initial concept explorations followed by Doppler Labs' end result that they launched in November of 2014. 
DUBS Concept Sketches
DUBS on Its Website
A screen capture from the GetDUBS' website. Click on this link to see more about DUBS Acoustic Filters.
Since my early involvement, the Doppler Labs team has clearly done a ton of amazing work and has created an impressive brand around DUBS, refined the design to fit with its function (although the spirit of these concepts remains) and have launched a smart sound filter called Here. Check out their Kickstarter.