Various earpieces (e.g. headphones, earbuds, behind the ear, hearing aids, and other devices that direct acoustic energy into an acoustic measuring device (e.g., ear)) have been designed for various uses. Many conventional systems have difficulty sealing in the ear canal. Custom fitting is used in the hearing aid industry by taking a mold of the subjects ear canal, and then designing a device which fits closely to the mold. There are issues with sealing since the ear canal changes in time, and the cost and time involved with just efforts.