If someone asks you, “what is sound?” could you answer the question?
Most of us, if we're honest with ourselves, may know a few fundamental things about sound.
However, at the end of the day, the majority of us have only skimmed the surface or recall bits and pieces from elementary school.
I know, you're nodding your head right now.
THE KNOWER OF THE MYSTERY OF SOUND KNOWS THE MYSTERY OF THE WHOLE UNIVERSE. – HAZRAT INAYAT KHAN
Now, whether you are a musician, an audiophile, or someone who is merely obsessed with sound, you are in the right place.
We are about to break it all down and finally answer the question, “what is sound?” in its entirety in a way that everyone can understand.
After you read this article, shopping for new sound equipment will be a piece of cake.
What Is Sound?
To answer the big question, we are going to have to start small.
So, let's start with the basics:
Sound is a wave — to be precise; it's a pressure wave that, “creates a mechanical disturbance in the medium in which it is directly adjacent to.”
Generally, the “medium” that ends up disturbed by the wave is the air, but sound can also travel through solids and liquids as well.
Check out this short video for a more detailed explanation:
An essential thing to remember here is that just because you can't see a soundwave, doesn't mean that it isn't physically there.
How Humans Hear
Now that you understand what a soundwave is let's talk about how the human ear manages to pick up those sounds.
Soundwaves consist of regions of compressions and rarefactions that occur as the sound travels away from its source:
- Compressions: areas of high pressure
- Rarefactions: regions of low pressure
The change in pressure hits the human ear, and that's what produces a sound.
The human ear
Our ears consist of three different sections:
- Outer ear
- Middle ear
- Inner ear
Sound hits your outer ear first.
Then, the outer ear works to funnel that sound through your ear canal.
“GET RID OF THE SHITTY SOUND. LIFE’S TOO SHORT.” – HANS ZIMMER
Once the soundwave hits your tympanic membrane (eardrum) in the middle ear, it causes it to vibrate.
But we're not done yet!
There are three bones in your middle ear:
Once the soundwave hits those bones, they transmit vibrations from your eardrum to your inner ear.
Then, the soundwave gets into your inner ear, and the cochlea there convert the vibrations into nerve impulses.
Finally, your auditory nerve receives those messages, already translated into nerve impulses, and carries them into your brain which is where your brain turns them into sound.
Check out the video below:
As you can see, the human ear is capable of an astounding number of processes, and they all happen almost instantly.
The Power Of Sound
Next, it's imperative that when someone tries to answer the question, “what is sound?” that they also understand the power of sound.
You should never underestimate the power of sound.
- Doctors in England used sound waves to kill cancer cells
- Playing music around plants will make them grow faster
- Sound can help balance out brainwaves and create cohesion between the two sides of your brain
- Ultrasound can help your wounds heal faster
- Music can help you improve your memory and learn things faster
Sound and shapes
Amazingly, Hans Jenny, a Swiss medical doctor, pioneered research that showed each sound produces a unique geometric shape.
Called cymatics — it's the study of “sound and vibration made visible.”
Check out the video below:
And if those shapes weren't cool enough, let's talk about Doctor Masaru Emoto:
Author of the book Messages from Water, Dr. Emoto studied the formation of crystals in water as he exposed the water to different sounds.
When Dr. Emoto played nice things like Mozart, prayers, and positive affirmations, beautiful crystals grew as a result.
“TONES THEMSELVES CORRESPOND WITH AND AFFECT SPECIFIC AREAS OF THE BODY. THE ANCIENTS UNDERSTOOD THAT A SIMPLE SOUND COULD REORGANISE THE BODY’S STRUCTURE. SOUNDS THAT ARE HARMONIOUS, ACTIVATE THE BODY AND CREATE HEALING.” EARTH: PLEIADIAN KEYS TO THE LIVING LIBRARY – BARBARA MARCINIAK
However, when Dr. Emoto played or yelled mean things like, “I hate you,” and, “I will kill you,” the resulting crystals were deformed and ugly.
Check out the video below:
So, as you can see, sound effects every human daily in more ways than most of us can imagine.
The Speed Of Sound
Now that you understand the power of sounds let's talk quickly about the speed of sound.
Check out the video below:
While the speed of sound is a constant, certain variables will affect how fast the soundwaves can move.
Those variables are:
- The type of gas (air, oxygen, carbon dioxide)
- The temperature of the gas
On average, though, the speed of sound through air is around 1,130 feet per second or approximately 750 miles per hour.
Measuring Sound Waves
Next, when it comes to measuring a sound wave, how fast it's going is not quite as crucial as other measurements — like volume and pitch.
Let's find out how you measure those.
First, the amplitude is the measurement of how powerful the wave is — which translates into how loudly the human ear hears that sound.
In other words, amplitude equals volume.
You measure the amplitude of a sound wave in decibels or dBA, and it defines the amount of pressure emitted by the wave.
You may also hear it called Sound Pressure Level or SPL.
- 0 decibels: the softest level that a person can hear
- 65 decibels: normal speaking voices
- 120 decibels: rock concert
For humans, sounds that are 85 decibels or higher have the potential to damage your ears permanently.
As the sound pressure (amplitude, volume) goes higher, the time it takes to damage your ears goes down, so be careful.
For example, sounds at 85 decibels will take up to eight hours to cause any damage while sounds over 100 decibels can cause damage after only 30 minutes.
Understanding Decibels Isn't As Hard As You Think
Now, for recording artists and musicians, understanding decibels on your equipment is a little more involved than just understanding what they measure.
First, most of us understand units of measurement on a linear scale, and decibels don't work that way.
Check out this video for a detailed explanation:
You can find the chart from the video if you click here.
Frequency aka pitch
If you want to answer the question, “what is sound?” the next thing you need to understand is the frequency of the sound wave — or the pitch.
The frequency of a sound wave is the measurement of how far it is between the peaks of the wave.
To measure the frequency, you want to measure the number of sound vibrations in one second.
The unit of measurement used to define the frequency (pitch) is Hertz.
Check out this short video on frequency and amplitude:
Let's break it down:
- The lowest A key on a piano is 27 Hertz
- The highest key on the piano is 4186 Hertz
- A human can hear sounds as low as 20 Hertz
Instruments used to measure sound
There are several different instruments you can use to measure sound including:
- VU meter
- Spectrum analyzer
- SPL (sound pressure level) meter
However, since it is 2019, instead of getting all that expensive equipment, you could just download an application like dB Meter to your smartphone.
People Started To Manipulate Sound Electronically Over 100 Years Ago
Starting from 1880 to the 1920s, Thomas Edison, Magnavox, and Victrola all used horns as the earliest means of manipulating sound.
Unfortunately, the horns alone could not amplify the sound all that much.
So, In 1906, a man by the name of Lee De Forest invented the first audio amplifier using a triode vacuum tube.
For a detailed explanation of how tube amplifiers work check out this video:
Then, in the 1970s, silicon transistors replaced the vacuum technology used in amplifiers.
For a detailed explanation of how a transistor amplifier works, check out this video:
While you can still find tube amplifiers today, most people prefer the transistor types because they are smaller and more efficient.
On top of that, the transistor types of amplifiers are also better at reducing distortion levels, and they are much cheaper to produce than the tubed versions.
What's A Watt?
Now that we are starting to answer the question, “what is sound?” we need to dig in and find out how wattages affect different equipment.
First of all, let's find out the answer to the question, “what is a watt?”
Check out the video below:
Generally, you can compare watts to miles per hour — watts measure how fast the electrons move “down the highway,” or the circuit.
Speakers And watts
Concerning the wattage readings on speakers:
Unless the speaker is self-powered, the wattage rating listed there is the maximum number of watts that the speaker can handle.
For example, if you have a 200-watt speaker and you attach a 250-watt amplifier to it, you're going to blow the speaker.
Amplifiers process sound and you measure the output with watts.
You can find the output of any amplifier listed right in the specs.
Again, make sure that your amplifier isn't pushing more power than your speakers can handle, or you risk damaging your equipment.
How Speakers Work
Speakers work by translating an electrical signal into an audible sound.
Now, that electrical signal can be an amp, stereo, microphone, or even these days a Bluetooth connection.
Speakers contain a permanent magnet as well as an electromagnet placed beside it.
The electromagnet is a metal coil that generates a magnetic field when the electric current flows through it.
The coil doesn't act exactly like a regular magnet, however.
Instead, as the pulses of electricity go through this electromagnet, the direction of the magnetic field changes rapidly.
Then, as the electromagnet's field changes, it alternates between attracted to and repelled from the permanent magnet, which causes rapid vibrations.
Those vibrations create a soundwave.
However, to get the sound outside the speaker, you need a few more parts.
The electromagnetic coil is also attached to a cone made from a flexible material like paper or plastic.
That cone amplifies the magnetic vibrations and pumps out the sound waves into the air and then into your ears.
Check out the video below:
Finally, concerning the cone the magnet uses to get the sound out there — many speakers have more than one.
To reproduce the many different frequencies of sound within a piece of music faithfully, high-quality speakers have different sized cones in them.
You see, with a different cone assigned to the high, mid, and low frequencies in a track, you are going to hear much more than you would from a speaker with only one cone.
Bass, Mids, And Highs
When you hear people speak about music equipment, you will often hear the terms bass, mids, and highs (treble) — those words describe the frequency.
Let's break it down:
- Bass: the frequency for bass is between 20 and 300 hertz
- Mids: 300 hertz to 4 kilohertz
- Highs (treble): anything above 4 kilohertz
Frequency ranges are not an exact science, so those numbers are estimates only.
To answer the question “what is sound?” you must first understand how frequency works when it comes to your sound components and equipment.
When you are shopping for sound equipment, you will often see the term “frequency response.”
Let's find out what that means.
You will see frequency response listed in the specifications for a ton of different products like speakers, headphones, amplifiers, receivers, and CD players.
To put it simply, the frequency response, “describes the range of frequencies or musical tones a component can reliably reproduce.
In other words, the frequency response is how well that particular component can reproduce the sounds we are capable of hearing.
Check out the video below for a detailed explanation:
While he was talking about headphones in the video, frequency response works in generally the same way across all equipment.
Additionally, while many purists go for a flat frequency response, some people prefer things like a bass boost, and that's okay too.
Drivers and crossovers and what they do
Before you can honestly answer the question, “what is sound?” you have to get a few more things straight concerning speakers.
First, it's vital that you understand that when you hear the term, “speaker,” that's describing the entire piece of equipment, housing and all.
However, when you hear the terms, “driver, box, and crossover,” those describe the critical stuff that produces the sound.
Let's break it down:
- Box: the box holds the drivers as well as the crossover network (when available)
- Crossover network: a device inside the box that divides the audio signal up between the different drivers
- Driver: these convert the electrical audio signal into sound waves
Sometimes, a speaker will contain many different drivers in one box, and at other times there are only one or two.
However, depending on what you need the speaker for, that's very much on purpose.
The Different Types Of Speakers And How You Should Use Them
Next, we are going to find out what the different types of speakers are as well as the best uses for each of them.
Passive, active, and powered speakers
As you learn and read about speakers, you will see them called passive, active or powered.
Check out this video that explains the whole thing:
- Passive speaker: does not contain an internal amplifier
- Active speaker: includes amplifier also includes an internal crossover system — in an active speaker the crossover system splits the frequency into different parts
- Powered speaker: has an amplifier built into the system
First up, we have the most popular type of speaker on the market: the dynamic speaker.
A dynamic speaker is usually a passive speaker.
A dynamic speaker also:
- Includes one or more woofer drivers
- Produces low-frequency sounds
- Has one or more tweeter drivers
- Might occasionally include rear drivers to amplify the sounds it's producing
Next, another favorite type of speaker for audio enthusiasts, especially the ones that like those low frequencies, is the subwoofer.
A subwoofer generally has one large woofer driver that produces low-frequency sounds as well as a port on the box to enhance them.
If you are shopping for a general speaker that produces a full range of sounds, a subwoofer isn't the one for you.
However, if you need to add a little more bass into your life, you're looking for one of these.
Next up, let's talk about horn speakers.
You might recognize the most common type of horn speaker from places like sporting events.
They look like this:
Horn type speakers have a lot in common with dynamic speakers when it comes to the drivers they contain as well as the frequency ranges.
Horn speakers also:
- Improve efficiency
- Eliminate the resonance caused by the materials used to make the speaker boxes
- Increases directivity: sound doesn't spread out from horn speakers like it does from other types
Electrostatic speakers feature one driver and a super-fine membrane over two conductive panels.
This setup results in a crisp, detailed sound for mid and higher frequencies — not so much for the lows.
This type of speaker comes with an outside power source, and you keep them plugged into a power outlet.
An ideal setup will contain both electrostatic speakers as well as dynamic speakers or a subwoofer for added bass.
Finally, we have a speaker design that produces quality highs and mids like the electrostatic speakers — planar magnetic.
A planar magnetic speaker uses a long metal ribbon suspended in between to magnetized panels.
This type of speaker is ideal, again, for producing precision high-frequency sounds, but if you need some bass, you will need s subwoofer or a dynamic speaker as well.
The Different Types Of Speakers Continued
On this mission to answer the question, “what is sound?” you have learned the different types of manufacturing techniques for speakers.
Next, let's take a look at the most popular speakers on the market and find out what they' do.
Studio monitor speakers
Now, we talked earlier about how many audiophiles prefer a flat frequency response.
Well, for a musician or music producer working on recording and mastering music, a studio monitor is essential.
Like we already discussed, most speakers have components in them that will enhance some of the frequencies.
However, you also learned that every different type of speaker has different settings.
So, when you are recording a track, you need to make sure those levels are as close to precisely what we hear with our ears as possible.
That way, when those other speakers play that mastered track, the levels are where they need to be.
So, to do that you need to listen to the soundwave on speakers that will reproduce the sound as flat as possible and that's what studio monitor speakers do.
Check out this video:
Some manufacturers sell studio monitor speakers as a set, and some of them sell one at a time — so keep that in mind when you're shopping.
When computers first popped on the scene, they came with tiny little internal speakers attached to the motherboard.
Well, the current generation of computer speakers come these days with a 2.1 system.
A 2.1 system means the speakers include two loudspeakers as a subwoofer.
Computer speakers are plug-and-play and often attach to your computer using a USB.
Floor standing speaker
Next up, if you are designing a home theater or other home sound system, you want to think about a floor standing speaker.
Provided, of course, that you have enough space.
You see, these speakers are around four feet tall, so if you live in an apartment, you may need something a little smaller.
You can get floor standing speakers in many different configurations with different drivers and such depending on your needs.
The majority of these speakers are passive or unpowered, so you're going to need a receiver or an amplifier.
Now, if you don't have room for those floor speakers, don't worry.
You can always get yourself some slightly smaller bookshelf speakers.
Bookshelf speakers are medium sized speakers that come in many different configurations.
This type of speaker is directional, which means that to get the full effect, they must face you and you will need an amplifier or a receiver to make them work.
Finally, we end our list of the most popular types of speakers with the creme of the crop — surround speakers.
If you want to have your home theater system sound like you are at the movie theater, a surround system is for you.
A surround system places several speakers in the room and works to create a 360-degree sound environment.
These types of speakers use multiple channels as well as different drivers to deliver sound to every corner of a room.
Common Problems With Sound
Of course, at some point, you are likely going to run into some issues with your equipment.
Let's discuss a few common sound issues and what they mean:
- Clipping: an audible distortion you can hear, and it happens when a circuit is overloaded
- Distortion: a difference between the source material and the sonic output of a sound system
- Acoustic feedback: the squealing sound you hear — it happens if the mic is too close to the speakers (you can stop it by turning down the mic)
Ways To Manipulate Sound Waves With Your Computer
Finally, we will round out our lessons helping you answer the question, “what is sound?” with a short chat about manipulating sound waves on your computer.
So, you finally got all the speakers and recording equipment you need, so what's next?
Well, if you want to record at home, you are going to want to grab a software program so you can master your work before you send it out.
There are so many of these programs out there, check out this video for more information:
These days, you can even get a ton of audio editing programs for free.
Now You're Ready To Blow Their Minds
And there you have it, folks.
Now, the next time someone asks you the question, “what is sound?” you are 100 percent ready to blow their minds.
Most importantly, the next time you're reading the specs on a piece of sound equipment, you're going to know exactly what those numbers mean.