Binaural Beats for the Technical Dummy
May 22, 2020
All of this talk about binaural beats. Just exactly what are binaural beats? Let’s explore this particular in three steps. First, we’ll talk about what sound really is. Then we’re going define frequency. And lastly, we’ll make use of these two definitions to explain specifically what binaural beats are.
Back to Fundamentals – What is Sound?
Here’s my definition: Sound is the sensation our brain creates (and we “hear”) when vibrations in the air cause the eardrum to move or vibrate.
We are surrounded by air – even though we don’t usually realize this except when the wind blows. Yet wind is a large and relatively slow movement – like the current in a stream. Sound is also the movement of air – yet much smaller and faster movements — like the ripples on a pond.
So , what exactly is sound? When we strike a drum, for instance, the head of the drum gets pushed in. Then, because it can kind of elastic, it springs back again. But it doesn’t stop where it had been. Because it has mass it will keep moving and pushes out (just like a swing continues to move to and fro after it’s pushed). Then, the particular drum head elastically snaps as well as continues until it pushes back in. And so on – it continues to vibrate back and forth until it runs from energy. We see this movement as vibration because it happens countless times a second.
That’s how sound is created – because each time the drum head pushes out, this pushes the air in front of it. Then that air pushes the air between you and the drum until the air around your ear pushes your eardrum in. When the drum head photos back into the drum, it sucks in the air around it. And that vacuum cleaner propagates through the air and sucks your eardrum outward. So , the particular drum head moving back and forth pushes the air between you and the drum back and forth very rapidly which pushes your own eardrum back and forth very rapidly. Whenever your brain senses your eardrum shifting, it translates those motions to the sensation we know as sound. So it’s all about air moving back and forth : and that’s why there’s no sound in room. No air – no audio.
What is Frequency? – The Speed associated with Sound
Frequency is simply how quick those sound vibrations occur. If the drum head vibrates 100 times per second it has a lower rate of recurrence than another drum head that will vibrates at 150 times another. We hear higher frequencies because higher pitch notes. So the thin string on a guitar creates a higher pitch or tone than a fat string because it weighs less so it can move back and forth quicker (and therefore pushes air backwards and forwards faster). And if we fret a string, we shorten the chain and the pitch gets higher. The shorter string weighs less than a lengthier string (less mass) so , once more, it vibrates faster.
What are Binaural Beats? (FINALLY! )
Let’s return to our drum example – only this time, we’ll be greedy and use two drums. If the drums vibrate at exactly the same frequency and if they vibrate together; the sound will be twice as loud. In other words, both percussion will push out at the same time so that the air that pushes our eardrum will be twice as strong and then each drums sucking will tug from our eardrums with twice as a lot force.