Basically, "two ears." One usage of the word is "binaural recording," which is a form of stereo recording meant to take advantage of the spatial perception of the human ear. Recordings are usually done using a pair of microphones mounted to a dummy head with roughly accurate models of the human outer ear, and the result when played back through headphones is extremely realistic and comparable to surround sound, though following an entirely different recording model. Binaural recordings aren't woo at all, and have nothing to do with binaural beats.[citation needed]
But we don't need any studies to tell us that different people can listen to different kinds of music and be affected. A lot of people who work out have a workout playlist on their iPod that keeps them energized. Some people listen to certain music to help them fall asleep. The Muzak company has built an industry on relaxing music that will keep people in the mood to shop. Music does affect our mood, and so we already have every reason to expect binaural beat recordings to produce the same effect. Different people may find certain binaural beats to be relaxing or energizing. But, we've never found any reliable indication that a binaural beat's connection to our brain is any deeper or more meaningful than any other music track. We do know for a reasonable certainty that specific claims made by most sellers of binaural beats are not credible, and that there is no reason to think that the effect they're claimed to produce will work for you.
You may recognize the "binaural recording" from ASMR, where the technique is often used. This explains why, if you search for "binaural" on YouTube, you get a mixture of two entirely different kinds of results: binaural beats and binaural ASMR recordings. It gets especially confusing in that there's some questionable and/or unexplored science surrounding each one.
It takes slightly more time to practice guided imagery, but this is a great way to leave your stress behind for a while and relax your body. Some find it easier to practice than meditation, as it allows more engagement of the conscious mind. You can focus on imagining relaxing environments you would love to visit, or on memories of your "happy place" for when you're stressed. You can play natural sounds in the background as you practice, to promote a more immersive experience.

They came to the table with the idea that the entrainment track would “cause” them to be in meditation, which it doesn’t. Or they thought that having the specific brainwaves the entrainment program promotes would “cause” them to be in meditation. It doesn’t. If you really understand the principles above, you’ll understand why. If you don’t grasp why yet, read these principles again and consider what they really mean. The answer is there.
I have read something different about theta waves and learning languages. A University of Washington study tested students resting brainwave activity before learning French. They found that students with a higher amount beta/gamma and a lower amount of delta/theta activity were better at acquiring a second language. When you are dominant in theta, that is the lowest and most deeply relaxed awakened state you can be in. I think it would be much harder to really concentrate, fully understand and learn new information while in a theta state, so I would personally consider using theta while studying.
Theta waves are associated with ➤ Increased sense of inner peace and emotional stability ➤ Deep relaxation ➤ Improved memory ➤ Heightened intuition and inspiration ➤ Calms the chatter of your mind ➤ Increased psychic abilities and sense of spiritual connection ➤ Speed healing, improved physical healing ➤ More restful sleep ➤ Release beneficial hormones related to health and longevity ➤ Reduce mental fatigue ➤ Reduction of anxiety and stress
By exposing an individual to repeatedly external stimulus which can be flashing lights and/or recurring sounds, the entrainment process consists in pushing the brain to adjust to match the frequency provided. Unlike other forms of neurotherapy which require the individual to actively respond to stimulus, entrainment creates an immediate neurophysical response which is instinctive and effortless for the person being provided with the light and/or sound combinations. The key outcome of the sensory stimulation is known as the ‘Frequency Following Response’.
A binaureal beat is created by playing a different tone in each ear, and the interference pattern between the slightly differing frequencies creates the illusion of a beat. It's intended to be heard through headphones, so there's no cross-channel bleed across both ears. Listen to this, I'll play a simple binaural beat, and I'll slide the pan control back and forth from one ear to the other. You can see that there isn't actually any beat, it's just an acoustic illusion:

Most of our Royalty Free brainwave entrainment music uses an audio technology known as "binaural beats". These binaural beats are embedded in the music in order to bring about desirable changes in brainwave activity, thereby encouraging various states of relaxation, deep meditation or sleep. When played with headphones, you may be able to hear the binaural beats as a subtle pulsing sound beneath the music.

This research investigates the brainwave entrainment process and aims to demonstrate the usefulness of such an approach within the framework of cognitive performance improvements. In the introductory part the theories regarding the neurophysiological structure and the psychological processing of the cognitive system are discussed, for each of their components that are considered to be relevant for this research. The hypothesis states that the stimulation with binaural beats and stroboscopic light, synchronized at 10.2 Hz frequency, will produce a positive change in cognition. The research variables are the cognitive performance (the dependent variable) and the brainwave entrainment (the independent variable). The brainwave entrainment program consists in the synchronized application of Alpha binaural beats and stroboscopic light, at a 10.2 Hz frequency, in a 30 minutes long session. The difference was made by the stroop effect based exercise that was used as a frame. There were 60 participants, divided into two independent samples. The two independent samples t test for the means differences was used in the statistical analysis. The obtained results by evaluations and by statistics confirmed this research's hypothesis, stating that the stimulation with binaural beats and stroboscopic light, synchronized at 10.2 Hz frequency, will produce a positive change in cognition.

Other than that the experience of those brainwave states is no different. Once we achieve a particular brainwave state using entrainment there is one significant difference to the experience and that is that we are usually still at a high level of consciousness. We’re not (hopefully) zoned out as we are when daydreaming or unconscious as we are when we’re sleeping. We maintain awareness and therefore we get to consciously experience what those brainwave states feel like in some detail.

Isochronic tones have only been proven to have an effect while you are listening to them, that’s why you won’t find me claiming anywhere that there are potentially positive long-term effects. Once the tones stop, your brainwaves are no longer being stimulated by the sound and so they stop being in sync with the tone frequency. For you to think you are still feeling the effects after all this time and from such a short time listening to them, I think it may be linked to anxiety. I know that some people who are new to this type of thing can build up a strong feeling of anxiety, after worrying about the potential effects brought on by fear of the unknown. I suspect the problem may be psychological with you worrying about the potential effects and keep repeating the experience from memory in your head. When you keep going over the same thing in your head like that and worrying about it, it’s easy to then spot other potential side-effects like how your nostrils and body temp is feeling, then making links back to that experience and labelling that as the reason. I think the best way to overcome this is to realise that the side-effects you are mentioning are completely unrelated, so there is nothing to worry about. These tracks are literally listened to for millions of hours a month on YouTube across loads of channels. If the effects lasted for a long time people would just listen for 5 minutes and come back in a couple of weeks. But people keep coming back to listen because that’s the only way to feel the benefit and effects…while you are listening to them. If you are unable to stop thinking and worrying about this on our own, I recommend that you speak to your doctor about it or a specialist in dealing with anxiety issues. I hope that helps.

There are differences between high (over 18 hertz), mid (15 to 18 hertz), and low range beta states (12 to 15 hertz). Low beta states are more relaxed while still being focused, making this a good range for many daily work related tasks like balancing a checkbook, making a shopping list, or driving to a new place. However, people with attention deficit disorder lack the mental focus for doing these types of activities, and studies have found people with ADD are often low in this range of beta brainwaves.
Maybe a favorite popular song, a certain piece of Classical music, a raucous dance beat, the pulse of Reggae, Indian, or African drums, or the chanting of Gregorian or Tibetan monks, but you probably know how the sound of music, drumming, or chanting is capable of transporting you into an altered and joyous state of mind and uplifting your spirits.

Delta brain state is related to the unconscious or super-conscious mind. Delta waves are the slowest of all five brainwave frequencies. These brain waves are generated in deep sleep and in very deep meditation. In the sleep cycle, the deepest of sleep states is called “Slow Wave Sleep” (SWS). In this phase, the brain begins producing very slow, large Delta waves. The deeper the sleep, the higher the amount of delta waves. This stage plays a vital role in health and well-being, especially because healing and regeneration processes are stimulated in this state. In the Delta state, you do not dream, you are completely unconscious.
Gamma brainwaves occur during creative thinking and processing of memory and language and in many learning activities. These brainwaves are not present at all when a person is under anesthesia, but return as soon as the person becomes conscious again. Multiple scientific studies have shown gamma brainwave entrainment to be helpful for reducing distractibility, improving short-term memory, improving motor coordination, and relieving migraine headaches.
Alpha (12hz – 8hz) – Awake, but deeply relaxed. Simply closing your eyes will produce alpha brainwaves. This category is associated with daydreaming, visualization, imagination, light meditation. Brainwave expert Anna Wise called the alpha range the bridge between beta and theta. (More information can be found in Wise’ book The High-Performance Mind)

A crossover RCT of a single session of theta stimulation in four healthy adults reported no significant improvement in verbal fluency or attention associated with the intervention and a reduction in immediate recall. Controlled comparisons reported significant benefit from the intervention in all three outcomes measured. Six pre/post studies reported significant benefit from the intervention for 19 of 28 cognitive outcomes.