For musicians who perform for large audiences, in-ear musician monitors (IEMs) are the current standard in musician technology. Sensaphonics developed the first Active Ambient IEM system. 3D allows artists to hear the ambient sound around them, naturally and with accurate directionality, while still retaining all benefits of isolation that custom ear phones provide. This product was engineered specifically to eliminate the boundary to adoption that artisits complain about most often when using IEM systems - acoustic isolation. They allow the musician to clearly hear the music they are making as the audience would hear it while still protecting the musician's ears from extremely loud amplification systems and audiences.
IEMs work best if they are custom molded to fit each musician's ears personally. However, there is still the option of universal fit musician monitors. Universal IEMs typically come with interchangeable foam or silicone tips to allow for a semi-custom fit.
Both ear molds and IEMs can be custom made (using a mold) to fit your unique ear shape, by a Hearing care Professional.
The ear impression that is used to make the ear mold or in-ear monitor is the most important part of the process in getting a good custom fit. The quality of the ear impression material and technique directly impacts the sound quality, sound isolation, and comfort that is achieved with the ear mold.
Because this part of the process is so crucial, it's important that you hire someone who is experienced and trained in making impressions for high-quality musicians earplugs.