Tuesday, November 27, 2012

Your Ear is Amazing Part Two

Good Day!

Time for part two, the how the ear understands music!

 This amazing video

And your amazing ear consists of an eardrum, tiny bones, and the cochlea. Today we will see how the cochlea understands music, pitch, chords, and tamper. Lets start off with pitch:

from Google
Pitch: The quality of a sound governed by the rate of vibrations producing it

The "rate of vibration" is called frequency. The frequency dictates what sound you hear. For each pitch or note there is one frequency. For example Middle C is 256 Hz about. This number corresponding to a certain group of hairs in the cochlea.

Now every pitch creates things called overtones. For Middle C the overtones are at 256*2 = 512 Hz. and  256*3 = 768 Hz. and ... you get the idea. For every multiple of the frequency a overtone is made. Your ear hears these tones if they are there or not. The hairs in the cochlea that hear 512 and 768 are triggered when a sound a 256 is played, but not as loud. Sound waves and their overtones look like this:
Harmonics = Overtones

A chord is made by playing notes and its overtones. so if you play 256 and 512 and 768 at the same time you get a major chord. You can also use different fractions to make different chord like 256, 256*3/2 = 384 and 512 to make a chord.

Music simply is made up of notes and cords that are just sets of frequencies which hairs in your cochlea translates to electrical signal for your brain to figure out. Music is fun and crazy.

I hope you learned something and enjoyed our blog. This is the last post, sorry if you were looking for more Sound Fun.

~The Sound of Silence Team

Thursday, November 22, 2012

Turkey Day Dubstep!

While I was looking for some Turkey Day inspiration I found the delightfully festive video below!
Born out of a town in England, the music genre of Dubstep slid on the music scene around 1999. With its heavy bass background and almost hypnotic beats dupstep has flooded the club scene!
With a frequency less than 90Hz and tunes that sound like Transformers getting it on Dubstep is perfect for a crazy night of dancing! 

The emerging nature of this new genre makes the direct classification of Dubstep difficult especially with qualities that overlap with other genres such as electronica, dance and hip hop.

Whether you like jams of Skillrex and the rest or not I hope you enjoy festive video and have a wonderful Thanksgiving!

Tuesday, November 20, 2012

Na na na na na na Bat-hearing!

To carry on our tradition of talking about cute things today's cute animal is...(drumroll)...

A baby bat!


Now, most people know that bats use echolocation to hunt, as they have VERY bad eyesight, but did you know that they actually do this in three ways? The bat will let out a very high, loud chirp and then listen for the sound reflections to come back, catching them with his giant (adorable) ears.

The first type of chirp is called constant frequency, which means that the frequency is steady. This type of sound is used to locate an item or object. The second type is called frequency modulated. This means that the frequency (how close the waves are together) gradually descends. This helps the bat to tell what type of object it is, as well as how far away.

Finally, the bat utilizes the Doppler effect (that is, the way sounds change in pitch as they get closer or further away) to modulate its speed in relation to its environment. These skills are so precise that bats can even tell the type of insect in order to decide on the most delicious dinner possible. 

Basically, bats are awesome.

But we knew that already. Photo here.

If you want to learn EVEN MORE about how bats hear and explore their surroundings, here is a cool power point presentation!

Monday, November 19, 2012

Les Paul Ultra - III

With thousands and thousands of guitars out in the world today, what feature can make you stand out from the competition? Enter the Les Paul Ultra - III. I was browsing the 2012 Guitar World Review Guide and I ran across this guitar  But what about this guitar grabbed my attention? Bedsides the beautiful instrument that Epiphone has created, it has the ability to plug into your computer via USB cable.

Along with the cable, included is Native Instruments' GuitarRig, which is software that allows you to play your guitar through the computer and allow you to play through a variety of simulated amplifiers and effects. All while listening through your computer speakers or headphones. This software includes a recorder, metronome, and a tuner.

For prices just around $750, this guitar is a great buy for a Christmas present for someone who you love.

Thursday, November 15, 2012

Your Ear is Amazing Part One

You are amazing. That is if you are human.

The human ear is one of the most interesting things sensors around. As complex as the eye, more sensitive than the nose, and important than the tongue. It is amazing.

Today we will be talking about how the ear works and how you take in sound. In part two we will explore music and notes, giving the ear and brain more complexity. To start lets explore how sound is made. Clap your hands!


When you clap your hands, the air around your hands moves and bumps into more air particles. These particles run into more and more air particles. This chain reaction of air bouncing around finally gets to your eardrum. The eardrum then vibrates and pushes against tiny bones. These bones push on the cochlea. The cochlea changes the vibrations in to neural signals and sends it off the the brain.

How the ear looks

The cochlea is the most interesting part. It takes a vibration and vibrates a fluid that then tickles cretin hairs depending on the frequencies in the sound wave. The clap you made has a particular sound wave that might look like this.
One Clap Sound Wave
That wave trigers some of the tiny hairs in the cochlea, which send electrical signals to the brain. The brain then interprets the incoming signals and matches it with signals it has heard before to gain meaning of the sound wave. But wait there is more! How many sounds are you hearing right now? Count them? Music, voices in the room, the heater or fan, your cell phone vibrating on the table.... your ear-brain combo takes all of these and can isolate them. Computers cant do this task well...yet. 

Thats all for today. Check out this really cool video on sound.

Friday, November 9, 2012

Sound Blasts!

I know we have talked about a couple of different topics, but I'd like to tie some of what we have talked about in our articles with a post about infrasound itself. Infrasound is sound we can't hear, or sounds below human hearing. and it can be used naturally(earthquakes, etc.) or by human means. This post will talk a little more on how humans have used it currently and in the past.
A Sound Villian
          We know sound can be deadly if used in the wrong hands. We talked about this a little more in depth here with LRAD. Infrasound itself can be related to many different things even ghosts as described here. To go more in depth of how it can be used for harm lets remember Iron Man the movie, when Obadiah uses a sound device to paralyze people? If you don't remember or want a refresher check out this video for a refresher.

Believe it or not this is a real application of sound devices that can be used. Infrasonic generators can cause negative emotions such as fear, anxiety, or depression, as well as biological symptoms like nausea, vomiting, organ damage, burns, or death—depending on the frequency and power level (Mark Rich). Similar devices have been used in the past and are being made by the U.S., Great Britain, Russian using low frequency sound waves in the development of acoustic weapons. These weapons are mostly being developed as a non-lethal approach to handling violence.

A Sonic Bullet Maybe?
Above is what I imagine a sonic bullet would look like if we could see them, but under normal conditions we can't. Police, military and other forms of security can use sound bullets to incapacitate people without bloodshed and has been used in the case of riot control in more modern times by shooting the sound at the low infrasound frequencies. In fact in 1971 there was a good use of infrasound where they used it for riot control which can be further explained and detailed here. That article also goes further into explanation on some different sound weapons as does this one which I also referenced above. So while fun to learn about sound can be a deadly and scary thing or it can be nice and calming. Definitely better than real bullets though in the way of law enforcement.

Hope you enjoyed this little info session on the details of what we have been talking about.
Please feel free to comment and subscribe =D

Ultrasound treatment explained!

So as a follow-up to the previous post here is a great presentation on focused ultrasound technology!

I Hope you enjoy!

Thursday, November 8, 2012

Silent- but not deadly!

Going off of a great articlerecommendation left on our previous post “Shake your Tail Feather”, I decidedto look more into all of those sounds we can’t hear- and dang are there a lot! Inthe next couple of posts I would like to tell you about ultrasound andinfrasound.

While you may be familiar with theclassic ultrasound images of babies and even baby animals, advancements withultrasound technology have been able to produce 3-D ultrasound images!

Dog ultrasound! Courtesy of Anchor Animal Hospital

Well that say it all! Image courtesy of University of California San Francisco

Ultrasound is also being used to treat conditions like carpal tunnel syndrome and scar tissue pain. Current treatment prostate cancer is currently using ultrasound to destroy cancerous tissues! The process refered to as High Intensity Focused Ultrasound, or  HIFU for short, involves ultrasound waves being focused on the damaged/cancerous tissues thus increasing the temperature at a very fast rate and destroying the cancer
"In order to understand the basic concept of how HIFU works an analogy can be drawn between HIFU burning prostate tissue and sun rays entering a magnifying glass to burn a leaf. When a magnifying glass is held above a leaf in the correct position on a sunny day the sun's rays intersect below the lens and cause the leaf to burn at the point of intersection. "~International HIFU

Image courtesy of International HIFU

 So forget barbequing ants in your backyard! How about we tackle cancer instead?

Monday, November 5, 2012

Sounds like learning... starting before birth?

We have all seen the mothers with headphones on there stomach and playing classical music. The theory behind this is that it will make the child smarter and promote healthy brain growth and learning? Is this true and should mothers that decide not to put headphones on their bellies, feel guilty?

Studies have shown that the fetus heart rate changes when listening to sounds either from music or just hearing its mother's voice. This suggest that the fetuses recognizes sounds from outside the womb. The sounds a fetus hears the most during its travels is its mother's voice. And in studies it shows that newborns will be calmer when hearing the mother's voice versus another voice never heard before. So we can assume that newborns can remember sounds that they heard in the womb.

It isn't too hard to make the conclusion that hearing music has a positive effect on a fetus, since most of the brain development happens during pregnancy  A study done by the Musical  Educators Journal found that babies who were exposed to music during pregnancy were more attentive after birth. These babies also had an increase in sound imitation and earlier vocalization.

But not everybody agrees with these findings. Gordon Shaw ( a researcher at the University of California) is once such person. Although he agrees that the change of heart rate of the fetus points to the fact that the unborn child can hear, that this isn't necessary a good thing. A change in heart rate could signal that the baby is uncomfortable with the sound. This could lead to more squirming and more discomfort on the mother.

Whatever you believe, the important part is to proceed with caution. The biggest mistakes mothers make is the volume of the music. The belief that the child is in the belly so the music needs to be loud is wrong. The amniotic fluid that surrounds that baby is very good at transmitting sound waves. So playing music too loud could damage the child's eardrum. Also if listening to music causes the baby to squirm more and increase discomfort on the mother, then exposure to music should be limited. Remember a happy baby means a happy Mother. That is all for today. Be sure to look for my next post in where I cover the effects of music after birth.