Well, if you've ever been on the job market for a position in big city orchestras, you'll notice that they have some very specific rules governing their blind auditions. All of the rules are designed to keep the playing field level. In addition to the rules preventing disclosure of gender (no coughing, perfume or cologne, that could give it away), and excluding amplification devices, they also exclude the use of brass, aluminum or magnesium "resonating bowls," since they offer such a large acoustic advantage. The exclusion dates back to the late 90s, when it was discovered that a young performer by the name of Chin Housin Crepier had won a series of auditions largely due to his use of what he claimed was a "spirit basin," but was nothing more than a brass resonator.
A few years later, he was at again--not with a resonator, but with some exotic hardwood shims, which he would place under the feet of his audition chair. It turned out that by slicing several rounds off of a super high end record clamp, he'd vaulted his way into the Berlin Philharmonic. Look it up!