Study Finds Reduced Ear Fatigue with REV33

Musicians and sound engineers agree that the REV33 makes their in-ear monitors (IEMs) sound better. The REV33 TrueSound™ ( is a small, powerful device that fits neatly between your receiver pack and IEMs. There are compelling design and functionality details but most importantly, with the REV33, the IEM experience is simply better… a lot better! Artists and engineers using the REV33 for performances lasting 90 minutes to over 3 hours consistently report that after-show ear fatigue is no longer an issue.

Dr. Craig Champlin of the University of Texas Communications Sciences and Disorders Department agreed to contribute his expertise to define and execute an objective methodology to test the REV33’s design and overwhelmingly positive user experience.

Dr. Champlin selected otoacoustic emissions (OAEs) testing due to its objectivity. For this pilot study, a touring band from Austin agreed to participate. Dr. Champlin measured the OAEs of each musician immediately before and after the show on 3 separate nights. The REV33s and the placebo REV33s were rotated so that each musician used the REV33 at least once. Those musicians using a REV33 with their in-ear monitors had significantly better results compared to those musicians using in-ear monitors without a REV33.

The chart below groups the data such that those not using a REV33 with their in-ear monitors are on the left and those using a REV33 with their in-ear monitors are on the right. The difference is stark and shows that those not using the REV33 with their in-ear monitors experienced a substantial drop in hearing sensitivity.

Published industry papers talk about ear fatigue and reduced hearing sensitivity in terms of Temporary Threshold Shift. Industry experts suggest that your ears need several days to recover and that without this recovery time, the probability of greater long-term damage increases. Artists and engineers do not typically get sufficient rest between shows and the effects of these Threshold Shifts, or ear fatigue, are also reported to build up over time. According to published paper by Dr. Rebekah F. Cunningham, OAEs can provide an early and reliable warning sign of cochlear dysfunction due to noise/music exposure before any problem is evident on the audiogram.

The REV33 focuses on keeping the signal clean as it is played into your ear. It reduces ear fatigue and increases sonic detail.

We have much more work to do before we can call the data above conclusive. However, here is what we do know. The REV33 focuses on keeping the signal clean as it is played into your ear. It reduces ear fatigue and increases sonic detail. The experience and positive effects on the performance has been consistently shown to become more and more noticeable with duration of use. And most importantly, our customers tell us that, when using the REV33 with their in-ear monitors, they no longer feel the effects associated with ear fatigue. This has been consistent feedback whether they are using universal-fit, single-driver IEMs or the most expensive custom-fit, 12-driver in-ears.

We have been so busy since our launch in March that it has taken us longer than expected to update our website with supported in-ear monitors and headphones. We appreciate your patience and are grateful for all of you who have so generously sent in their expensive, custom-fitted in-ears for characterization. These acts of generosity are helping many others get their REV33 sooner. At REVx Technologies, we are committed to delivering great products for your ears.

Brett Butler, CEO of REVx Technologies, Inc