The earbuds stimulate the vagus nerve, which sends signals from the brain to most major organs, in order to activate the resting and digestion functions that leave you feeling relaxed and pleased. In theory, you can deal with a bad day at work or recover from an intense workout just by listening for a short while (Neuvana recommends two 15- to 20-minute sessions each day). A mobile app optionally pairs the stimulation with your music library or ambient sounds to help the stimulation reflect your listening habits and environment.

Does it work? Maybe. When we first tested Neuvana's tech, the stimulation did produce a "mild sense of elation," so there appears to be something to the basic concept. The company is keen to tout the medical expertise behind its Xen buds -- there's some scientific basis for what's happening. The question is whether or not the stimulation will have a lasting impact on your health, such as improved sleep and better concentration. You can't test those in a short, highly controlled tech demo. There is a 30-day money-back guarantee period, at least, so it might not hurt to give these a try if you're intrigued by the concept.