UPDATE: IMPORTANT WARNING
12/24/2019 UPDATE: After just 10 minutes of using this gamma brainwave entrainment device, my tinnitus (which I have had for years, but which has never been a bother) was amplified ten fold to the point where it is distressing and headache inducing and has already prevented me from sleeping a night.  The product comes with disclaimers warning against seizures for those who are prone (I am not), but there is no warning about tinnitus (ringing in the ears), and so I feel compelled to issue one here should anyone else be subject to this symptom.  I'm worried enough about it that I've already booked an appointment with a neurologist to get a brain map done in hopes of finding a countervailing frequency that can remedy this awful ringing in my head.  I noticed this effect almost immediately and should have heeded it; should this happen to you, do yourself a favor and discontinue use at once!<br /><br />On top of this, the charging cable has a short in it and the unit cannot be reliably charged, so I am returning it based on this alone.  If only that were my only issue!  Be forewarned.<br /><br />------------------------------<br />Original Review:<br /><br />I suppose this does what it says it will do: it plays an audible tone (maybe 1khz?) pulsing at 40 cycles per second.  It looks like a tiny (one inch square) ipod player, replete with standard headphone jack, usb micro port, and a mini SD card.  For some reason, they include ear buds with the unit; I'd have preferred they saved the money on the buds (which are common enough) and spent a bit more on the quality of the unit.  I'm tempted to see if I can transfer whatever audio file is on the SD card to my phone.  Or just download a binaural brain app that will play the same cycles... but typically, a gamma wave of 40 hz is inaudible.  I'm assuming the 1khz tone cycled 40 times per second matches what was performed in the gamma wave entrainment studies.<br /><br />I plan to use this nightly along with the 40hz lights to see if it has any noticeable affect on my cognitive state.  Time will tell.
Rating: 2 stars