Essentials: How Hearing & Balance Enhance Focus & Learning

**Andrew Huberman** (0:00)
Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science-based tools for mental health, physical health and performance. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, we're going to talk all about hearing and balance, and how you can use your ability to hear specific things and your balance system in order to learn anything faster. The auditory system, meaning the hearing system and your balance system, which is called the vestibular system, interact with all the other systems of the brain and body, and used properly can allow you to learn information more quickly, remember that information longer and with more ease. And you can also improve the way you can hear. You can improve your balance. We're going to talk about tools for all of that. As many of you know, I've been taking AG1 daily for more than 13 years. However, I've now found an even better vitamin mineral probiotic drink. That new and better drink is the new and improved AG1, which just launched this month. This next gen formula from AG1 is a more advanced clinically backed version of the product that I've been taking daily for years. It includes new bioavailable nutrients and enhanced probiotics. The next gen formula is based on exciting new research on the effects of probiotics on the gut microbiome. And it now includes several specific clinically studied probiotic strains that have been shown to support both digestive health and immune system health, as well as to improve bowel regularity and to reduce bloating. As someone who's been involved in research science for more than three decades and in health and fitness for equally as long, I'm constantly looking for the best tools to improve my mental health, physical health and performance. I discovered and started taking AG1 way back in 2012, long before I ever had a podcast and I've been taking it every day since. I find that it greatly improves all aspects of my health. I just feel so much better when I take it and I attribute my ability to consistently work long hours over all these years while also maintaining a full life, having tons of energy, sleeping well, not getting sick, et cetera, in large part to AG1. And of course I do a lot of things. I exercise, I eat right, et cetera. But with each passing year, and by the way I'm turning 50 this September, I continue to feel better and better and I attribute a lot of that to AG1. AG1 uses the highest quality ingredients and the right combinations and they're constantly improving their formulas without increasing the cost. So I'm honored to have them as a sponsor of this podcast. If you'd like to try AG1, you can go to drinkag1.com/huberman to claim a special offer. Right now AG1 is giving away an AG1 welcome kit with five free travel packs and a free bottle of vitamin D3 K2. Again, go to drinkag1.com/huberman to claim the special welcome kit with five free travel packs and a free bottle of vitamin D3 K2. Can you hear me? Can you hear me? Okay, well, if you can hear me, that's amazing because what it means is that my voice is causing little tiny changes in the airwaves, wherever you happen to be, and that your ears and whatever's contained in those ears and in your brain can take those sound waves and make sense of them. And that is an absolutely fantastic and staggering feat of biology. And yet we understand a lot about how that process works. So what we call ears have a technical name. That technical name is oracles, but more often they're called pinna, the pinna, P-I-N-N-A, pinna. And the pinna of your ears, this outer part that is made of cartilage and stuff, is a range such that it can capture sound in the best way for your head size. So the shape of these ears that we have is such that it amplifies high-frequency sounds. High-frequency sounds, as the name suggests, are the squeakier stuff. So we have low-frequency sounds and high-frequency sounds and everything in between. And those sound waves, for those of you that don't maybe fully conceptualize sound waves, are literally just fluctuations or shifts in the way that air is moving toward your ear and through space. In the same way that water can have waves, air can have waves, okay? So it's reverberation of air.
Those come in through your ears and you have what's called your eardrum. And on the inside of your eardrum, there's a little bony thing that's shaped like a little hammer. So attached to that eardrum, which can move back and forth like a drum. It's like a little membrane. You got this hammer attached to it. And that hammer has three parts. For those of you that want to know, those three parts are called the malleus, incus and stapes. But basically you can just think about it as a hammer. So you've got this eardrum and then a hammer. And then that hammer has to hammer on something. And what it does is it hammers on a little coiled piece of tissue that we call the cochlea. So this snail shape structure in your inner ear is where sound gets converted into electrical signals that the brain can understand. Now the cochlea at one end is more rigid than the other. So one part can move really easily and the other part doesn't move very easily. And that turns out to be very important for decoding or separating sounds that are low frequency and sounds that are of high frequency, like a shriek or a shrill. And that's because within that little coiled thing we call the cochlea, you have all these tiny little, what are called hair cells. Now they look like hairs, but they're not at all related to the hairs on your head or elsewhere on your body. They're just shaped like hairs. We call them hair cells. Those hair cells, if they move, send signals into the brain that a particular sound is in our environment. Now, this should stagger your mind. If it doesn't already, it should, because what this means is that everything that's happening around us, whether or not it's music or voices, all of that is being broken down into its component parts. And then your brain is making sense of what it means. Your cochlea essentially acts as a prism. It takes all the sound in your environment and it splits up those sounds into different frequencies. And then the brain takes that information and puts it back together and makes sense of it. So those hair cells in each of your two cochlea, because you have two ears, you also have two cochlea, send little wires, what we call axons, that convey their patterns of activity into the brain. And there are a number of different stations within the brain that information arrives at. Before it gets up to the parts of your brain where you are consciously aware. And there is a good reason for that, which is that more important than knowing what you're hearing, you need to know where it's coming from. And our visual system can help with that, but our auditory and our visual system collaborate to help us find and locate the position of things in space. That should come as no surprise. If you hear somebody talking off to your right, you tend to turn to your right, not to your left. If you see somebody's mouth moving in front of you, you tend to assume that the sound is going to come from right in front of you. Disruptions in this auditory hearing and visual matching are actually the basis of what's called the ventriloquism effect. The ventriloquism effect can basically be described in simple terms as when you essentially think that a sound is coming from a location that it's not actually coming from. The way you know where things are coming from, what direction a car or a bus or a person is coming from is because the sound lands in one ear before the other. And you have stations in your brain, meaning you have neurons in your brain that calculate the difference in time of arrival for those sound waves in your right versus your left ear. And if they arrive at the same time, you assume that thing is making noise right in front of you. If it's off to your right, you assume it's over on your right. And if the sound arrives first to your left ear, you assume quite correctly that the thing is coming toward your left ear. But what about up and down? If you think about it, a sound coming from above is going to land on your right ear and your left ear at the same time. A sound from below is going to land on your right ear and your left ear at the same time. So the way that we know where things are in terms of what's called elevation, where they are in the up and down plane is by the frequencies. The shape of your ears actually modifies the sound depending on whether or not it's coming straight at you from the floor or from high above. Now this all happens very, very fast in a subconscious, but now you know why. If people really want to hear something, they make a cup around their ear. They essentially make their ear into more of a fennec fox type ear. If you've ever seen those cute little fennec fox things, they have these big spiky ears. They kind of look like a French bulldog, although they're kind of the fox version of the French bulldog. These big, big tall ears, and they have excellent sound localization. And so when people lean in with their ear like that, with their hand like this, if you're listening to this, I'm just cupping my hand at my ear. I'm giving myself a bigger pinna. Okay, and if I do it on the left side, I do this side. And if I really want to hear something, I do it on both sides. Okay, so this isn't just gesturing. This actually serves a mechanical role. And actually, if you want to hear where things are coming from with a much greater degree of accuracy, this can actually help because you're capturing sound waves and funneling them better. I'd like to take a quick break and acknowledge our sponsor, 8 Sleep. 8 Sleep makes smart mattress covers with cooling, heating and sleep tracking capacity. 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So now I want to shift to talking about ways to leverage your hearing system, your auditory system, so that you can learn anything, not just auditory information, but anything faster. I get a lot of questions about so-called binaural beats. Binaural beats, as their name suggests, involve playing one frequency of sound to one ear and a different frequency of sound to the other ear. And the idea is that the brain will take those two frequencies of sound, and because the pathways that bring information from the ears into the brain eventually cross over, they actually share that information with both sides of the brain, that the brain will average that information and come up with a sort of intermediate frequency. And the rationale is that those intermediate frequencies place the brain into a state that is better for learning. And when I say better for learning, I want to be precise about what I mean. That could mean more focus for encoding or bringing the information in. As you may have heard me say before, we have to be alert and focused in order to learn. So can binaural beats make us more focused? Can binaural beats allow us to relax more if we're anxious? So what do the scientific data say about binaural beats? The science on binaural beats is actually quite extensive and very precise. So sound waves are measured typically in hertz or kilohertz. I know many of you aren't familiar with thinking about things in hertz or kilohertz, but again, just remember those waves on a pond, those ripples on a pond, if they're close together, then they are of high frequency. And if they're far apart, then they are low frequency. So if it's many more kilohertz, then it's much higher frequency than if it's fewer hertz or kilohertz. And so you may have heard of these things as delta waves or theta waves or alpha waves or beta waves, et cetera. Delta waves would be big, slow waves, so low frequency. And indeed, there is quality evidence from peer-reviewed studies that tell us that delta waves like one to four hertz, so very low frequency sounds, can help in the transition to sleep and for staying asleep. And that theta rhythms, which are more like four to eight hertz, can bring the brain into a state of subtle sleep or meditation. So deeply relaxed, but not fully asleep. And you'll find evidence that alpha waves, eight to 13 hertz, can increase alertness to a moderate level. That's a great state for the brain to be in for recall of existing information.