Simply put, ‘sound’ is something that is both heard and physically felt. It is basically noise that is picked up by the ear (acoustically) with a set of characteristics that allow us to differentiate one sound from another. When a sound is created, the sound must travel to our ears, through a sound wave, for it to be picked up or heard therefore the environment around the sound, as well as any obstacle between the sound and our ears, can affect the sound before it reaches its destination.
Although sound waves cannot be seen they would resemble the ripples that result from something dropping into a body of water. The resulting ‘ripple /wave’ is similar to what is created with air particles at the moment a sound is created and these sound waves are how sound travels from the source of the sound to our ears. Therefore sound requires an origin, a method of travel/transmission, and a destination.
The human ear can then receive the sound and then further break it down to different components that make up a sound’s unique qualities and that therefore make one sound distinguishable or recognizable from another sound.
Note: I chose to couple length with Amplitude/Volume however once again, distance can very well also have been height or width. Since height and width have already been used with pitch and tone, we will use length to explain Volume.
There are 3 main events in life, namely birth, living, and death. Birth is the entrance while death is the exit, and living is what happens between the entrance and exit. This principle can also be applied to our five senses since sight, smell, taste, hearing, and touch all require the same 3 events for us to experience them. Let me explain…
All senses have a beginning, a middle, and an end as they all require a construction (creation or introduction), a peak or existence, and then a deconstruction (destruction or decomposition). Sound is no exception and therefore sound has it’s own terms to describe each of these events. In music, these events refer to Attack, Sustain, and Decay. In essence they respectively refer to an increase (or start), a stable period of activity (middle), and a decrease (end) in volume … over time.
Some sounds occur quickly therefore the start and end of the sound are spaced relatively close to one another however for longer sounds it is easier to notice a start, middle, and end. If you compare this to a sound from your mouth, there is the period in which sound begins but where your mouth is still closed (such as the moment where the sound is still a hum), then the mouth opens and the sound is at it’s clearest, and then the point where the mouth closes once again which is the end of the sound. The opening of the mouth can be fast or slow therefore the ‘attack’ or introduction of a sound can be fast or slow. At its peak, the sound is at it’s strongest and most stable after which the mouth begins to close once again, resulting in a decrease in volume. Once again, the closing of the mouth can be fast or slow, therefore the ‘decay’ or exit of a sound can also be fast or slow.
Attack represents how a sound fades in or enters our perception. This ‘fade in’ can be fast, which would mean that we would hear the sound quickly after it is produced, or it can be slow which would mean that we would hear the sound fading in since it’s volume is slowly increasing over time. If using equipment to set the attack of a sound, you might have an attack knob which might be labeled with numbers from 1 to 10 where 1 has a slower attack while 10 has a fast attack. Conversely, the equipment’s instructions might indicate that these numbers are a reference to time and might therefore prefer to use the number 1 as a fast attack and higher numbers as a slower attack since an increase in time between two events is considered to be a slowing of time. Regardless of the usage, the takeaway is that the attack or introduction of a sound can be fast or slow, and literally any speed in between.
If comparing attack to automobiles, attack would be similar to takeoff speed. Some cars accelerate quickly while others have a slower acceleration before reaching cruising speed. The cruising speed would be the point that can be ‘held’ or sustained for a period of time and the slowing down or deceleration would be similar to ‘decay’. The ‘acceleration’ is therefore the ‘attack’. Percussive instruments such as a snare, a cymbal, or a bell, reach their loudest volume point almost immediately and are therefore referred to as sounds with a fast attack. The attack is therefore the actual increase in volume at the beginning of a sound before the note reaches it’s peak point. A cat’s meow or a cow’s mooing are examples of a slower attack as there is a slight delay before their sounds are at their peak. A truck for example, has a slower acceleration before it reaches it’s maximum speed.
A dictionary will describe attack as a ‘hit’ or ‘strike’. Attack is often described as an act of violence or hostility however in a musical sense it is mostly about the introduction of the act itself rather than the fact that it is violent as it refers to the act of ‘hitting’ something to create a sound/note. Blowing, plucking, strumming, picking, bowing or any act that ‘disturbs’ the surrounding air particles to generate a sound wave is considered an ‘attack’. A physical attack can be considered a ‘disturbance’ which is closer to the musical sense of it as ‘disturbance’ implies that it was an intentional act to create a reaction (in this case to air particles).
Attack would be the head, while Decay refers to the tail end of a sound. Decay is therefore the way a note ends. It is the ‘deceleration’ of the car’s speed … or in the case of sound, the drop in volume over time after the peak is reached. It is the tail end of the sound. Using the example of a cymbal, if the cymbal is left to ring out, the decay is very slow as the sound fades off until it is no longer heard. A snare drum however is a very short sound as the decay is quick. Attack = Fade In … Decay = Fade Out.
Sustain is the duration of a note. It refers to the point after the attack and before the decay. In shorter sounds it can be simply the ‘peak’ since the note is not actually sustained for an amount of time that is easy to measure (or hear), however in longer sounds, the peak drags on before the decay begins. This is the ‘cruising speed’ of a car where the car is neither accelerating nor decelerating and is the point where the sound is at it’s fullest and stable. A fast decay does not necessarily mean the sustain or duration of a note is also short. A note can still sustain for a period of time and the decay can still be quick as it refers to the drop in volume at the end of the peak or stable part of the sound. The drop can be slow or fast similar to a car that is decelerating or breaking instantly. The same applies to the attack in that the attack can be slow or quick before it reaches it’s peak and begins to sustain.
That being said, a car may accelerate and decelerate multiple times during its journey before it stops however each acceleration is a new beginning therefore the acceleration is always preceded by a deceleration even if the end of the sound was not audible. It was simply a fast ending.
*Note however that an attack is not only fast or slow which reflects the speed at which a sound is introduced, it can also be measured in intensity therefore you will also see terms such as ‘strongattack‘ or ‘softattack‘ as a sound can still have a soft yet fast attack or a strong but slow one. This can be explained with a physical act such as a punch or slap. Both can be very quick except a punch may be stronger than a slap therefore their individual intensity are different. The takeoff speed of a diesel engine race car has a stronger attack than an electric engine race car however both can theoretically accelerate at the same speed. One will simply be louder than the other since the attack was stronger.
A sound can have a soft yet fast attack or a strong but slow one. The combination itself will depend on the instrument itself as well as what a piece of music requires.
The natural sound of an instrument has it’s own attack, sustain, and decay giving it its unique quality (tone and timbre) however most instruments also allow the possibility to control their dynamics so that stronger or softer, faster or slower attacks can be applied as needed.
If a piece requires an instrument that sounds softer, it may prefer a violin over a trumpet. Although the trumpet has the possibility of being played softly, the natural sound of the instrument has a stronger attack than a violin. Similarly, the violin can be played strongly however it may lack the strength that the composer is looking for to correctly express the emotion of a piece of music.
A weight lifter for example is stronger than a soccer player as they’ve trained themselves to lift heavier weights however a soccer player is more agile and can therefore move faster. Neither is better or worse on their own since they both have ‘strength’ in their own ways therefore this is not a reflection on either of their abilities or qualities. Depending on the scenario in question however, one may have better success.
Dynamics will be explained in more detail in a later lesson however it is important to understand that the terms we are using to describe ‘sound’ will also reappear in other areas. Thankfully, they will also still mean the same thing.
The Timbre of a sound is the term used to identify a sound’s ‘fingerprint‘ as it represents that quality that makes it unique from another sound. This is directly linked to the primary and secondary frequencies and their specific volumes. Each instrument will have its own volume settings that will give it it’s unique sound.
String instruments can have similar timbres as their sounds and construction are similar enough that they would share certain sound qualities. The same would apply to wind instruments, reed instruments, and percussion instruments. The various instrument families all have their own characteristics that allow us to recognize the family that any given instrument might belong to however timbre can go deeper than that as well.
The difference between a violin and an acoustic guitar for example is pretty obvious even though each instrument might be playing the same note, or have the same equalization settings. They both belong to the string family however one is played with a bow while another is plucked or played with a pick. Using a guitar pick on a violin for example will result in a very guitar-like sound just as using a bow on a guitar will sound much closer to a violin. Their body size and construction is different however, therefore each will still have a unique sound. The timbre is how you know that one instrument is audibly different from another.
It isn’t as easy to distinguish two violins from one another since they have similar timbres therefore it’s safe to say that the timbre is the overall expectation we have of an instrument’s sound. There may still be slight and perhaps even obvious differences between two violins since a slight variation of wood or even hardware (ie. tuning pegs or strings) can affect the instrument’s tone in an obvious way however the timbre is basically the overall sound of an instrument that allows you to recognize a particular sound as coming from a violin and not a cello, piano or guitar.
It is possible to actually modify the tone drastically enough to cause an instrument to no longer sound like it is expected to however if the instrument is no longer recognizable or modified in such a way that it would sound like a different instrument altogether, you can say that the timbre has been affected and the new sound is actually a different instrument. With modern technology for example, you can make a guitar sound like a violin, or an organ… in this case, while you are using a guitar as a means or tool to making music, the timbre of your resulting sound is of an organ, not a guitar.
I coupled Tone with Width since I had already decided to place Pitch with Height however, once again, there is no reason to look at tone as something that is measured as width. The reason I am using length, width and height is to show that sound, like objects has different dimensions that make up it’s form. If you turn a box on it’s side for example, the height is now used to measure a different side, regardless of it’s actual measurement. It is however, a different measurement that helps us understand the dimensions of an object.
While Pitch describes the frequency at which the sound oscillates/vibrates, Tone refers to the quality of the sound itself. Therefore what pitch is to height, tone is to width in that it measures a different dimension or quality of a sound. Once we have established a pitch to focus on, we’ll want to describe what that pitch sounds like in terms of tone. Unfortunately Tone is also measured in frequencies therefore it can cause confusion with frequencies of pitch. There is actually a direct relationship however equalization refers to the bass, middle, and treble of a sound. Anyone who has listened to music on a medium such as radio, television, or even a phone has noticed that they can modify the bass, middle, and treble settings to their preferences. Modifying these settings does not change the actual song itself however you are choosing to amplify or reduce the volume of bass, middle, or treble frequencies in a way that is more pleasing to your ears. Equalization can be applied to the sound that is being created or to the equipment used to listen to the sound/musictherefore it can be both a part of the original sound as much as a preference setting while listening back to the sound. Pitch however is predetermined by the musician therefore the act of modifying the pitch would actually be a modification to the song altogether. More on this later.
When a sound is created, it is actually made up of multiple frequencies that are occurring at the same time. There is however one fundamental frequency, which is the main and most obvious sound you hear, giving the perception that there is only one frequency however there are actually multiple other frequencies, called enharmonic tones, that are taking place at different volumes and at the same time, which give it the unique sound you are experiencing. The enharmonic tones are related to the fundamental frequency, usually a combination of doubling the frequency but not limited to doubling, therefore the elimination of any of the secondary frequencies will not change the pitch of the sound since the fundamental frequency is still present and even implied by all the other frequencies. Removing the fundamental frequency will automatically also remove the secondary frequencies to a certain degree since they only exist because of the fundamental frequency (and how our ears interpret it) therefore the pitch would still be the same except much quieter since ‘removing’ a frequency is simply lowering of the volume of that frequency. Changing the frequency by making it faster or slower however will affect the pitch as you are speeding up/slowing down the fundamental frequency (which will also automatically move all other secondary frequencies along with it) however the adding or removing of a frequency (ie. Using an equalizer), is simply the act of raising or lowering the volumes of frequencies.
A high pitch can therefore still have lots of bass frequencies present and a low note can still have lots of treble since tone frequencies are more related to the quality of the sound itself and not pitch.
Quick side note about Bass: When we refer to ‘bass’ we are referring to sound frequencies rather than a bass guitar instrument. The reason a bass guitar is called bass is because it is usually used to play lower sounding notes (lower pitches) as accompaniment to a guitar for example, however even a bass guitar can have specific bass, middle, and treble frequencies in it’s tone or sound spectrum. A bass guitar is therefore not only bass frequencies. Perhaps it could have been named differently to avoid confusion … just as a French Horn is named differently from a Trumpet. This is why you will often see the term ‘bass guitar’ when referring to the instrument instead of tone (which is simply ‘bass’).
As stated, a note has multiple frequencies in play at any given moment regardless of the pitch being played. Bass frequencies are therefore lower sounding frequencies within the audio/sound spectrum (300 Hz and below) while Middle frequencies are slightly higher (around 600 Hz) , and Treble frequencies are much higher sounding (1 KHz and up). The names ‘bass, middle, and treble’ are simply names given to a range of frequencies so that we don’t need to memorize actual frequency numbers however there are specific times, especially for sound engineers (and perhaps ear specialists) where the actual frequency number is necessary.
Since Tone and Pitch are directly related, a person who has trouble hearing treble frequencies will also have trouble hearing higher pitches clearly. Modifying the volume levels of various frequencies can help a person hear something better as you can target specific frequencies that may be troublesome. Tone and Pitch can be compared to a man and woman where: A man usually has a lower pitched voice and a woman has a higher pitched voice however if they are both speaking through a microphone, you can still adjust their individual tone by adding more bass, middle, or treble to their sound yet they would still each sound like a man or a woman. Tone will not change pitch however it can help make sounds brighter or darker sounding. Adding more treble would make either voice a little clearer as higher frequencies tend to be easier to hear, while adding more bass, or middle, would help their voices sound fuller or thicker, and even muddier or ‘boomy’ if too much is added or if too much treble is removed.
The first and most obvious element we recognize in music is pitch in my opinion. A melody is made up of various pitches or notes occurring at specific intervals/distances from one another that make them noticeable, pleasing or not. Melody is usually what captures people the most about music as a well composed melody can convey an emotion that we can relate to. The most natural instrument used to communicate a melody is the voice. The attempt to recreate sounds or melodies requires our ability to recognize pitches, sound quality, and duration of notes and while it isn’t necessary to know the science itself in order to imitate these sounds, you would need to intuitively recognize these characteristics at a bare minimum.
So what are pitches? If you take whistling as an example, you can see how changing the size of the space between your lips and the placement of the tongue affects the sound you make. Similarly, if you take a balloon filled with air and pinch the balloon to let a small amount of air out, you can control the amount of air rushing out of the balloon. Loosening the opening allows more air to pass through and for the rubber to vibrate at a slower speed while stretching/pulling the rubber farther apart will tighten the opening causing the rubber to vibrate at a much faster frequency. The faster vibration results in a higher sound while the slower vibration results in a lower sound. This is exactly what occurs when singing except the tightening and loosening occurs in the vocal chords.
When playing guitar, there is a slight difference as it is an actual string that is vibrating however the concept is similar in that the slower a string vibrates, the lower the sound will be and as you shorten the string by holding subsequently higher frets, the vibration of the string increases and therefore causes subsequently higher pitches/notes/sounds.
A balloon, vocal chords, or whistling sounds are a result of air rushing through as it is the air that causes the vibration of the balloon or vocal chords. In the case of a guitar, since it is not a wind instrument but rather a string instrument, the string must be struck, or plucked, for it to vibrate, just as a percussion instrument must be hit for it to emit a sound.
Pitch can therefore be initiated through the act of striking, plucking, or blowing air onto or through something for which the frequency of the vibration can be controlled in a way that will cause a rise or drop in pitch. The movement of the air particles, or sound wave, can then travel to a receiver … recording device or the human ear, which can then interpret the tone, pitch, and amplitude signals into sound.
Sound waves can be compared to dropping a rock into a lake. A small pebble will create multiple small ripples while a large rock will create lesser but bigger ripples over the same distance. The ripples, although they are moving water particles instead of air, would be a visual representation of how sound waves work. Over time the height of the ripple will begin to decrease until the ripple is no longer visible, just as the volume of a sound wave will decrease until it is no longer heard.
In music, an A note/pitch is a frequency that is vibrating at 440 Hz while a G note is vibrating at 392Hz and a B note which is higher than A would be vibrating at 493.88 Hz over a similar moment in time (ie. millisecond). Doubling the frequency (or speed) would mean that you will hear the same note yet at a higher pitch … for example an A note vibrates at 440Hz and is called A4 while a note vibrating at 880Hz is still an A but is called an A5 since it is still an A but at a higher pitch or ‘octave’. Octaves will be explained in better detail soon so don’t be too concerned about not understanding this term right now. The importance of this section is to understand that pitch is determined by the speed at which the sound wave is vibrating within a given duration and that the number of repeated vibrations, or ‘repetitions’ are what is called ‘frequency’.
That said, if you do experiment with creating different pitches, you’ll notice that at some point you won’t hear very high or very low pitches. This does not mean that there is no sound presently being made however, as the human ear can only hear a specific range of frequencies (20 Hz to 20,000 Hz). Younger people have a wider range while older people have a narrower range of hearing as they lose their ability to hear over time … either due to aging, from over exposure to louder music throughout their lives, or both. While increasing volume might allow you to hear some of these frequencies that are normally out of our range of hearing, there is a limit to what our ears can handle both in frequency and in volume therefore you will eventually stop hearing certain frequencies. Dogs, for example, have a different hearing range from humans and can therefore hear much higher pitch frequencies than humans. This is why a dog whistle is heard by a dog but not a human.
Note: Be very careful if you attempt to raise the volume in an attempt to hear these sounds as you may actually damage your hearing in the process since your ear is still attempting to process the sound even though it may not have the ability to convert it to a signal that the brain can interpret.
I could just have easily compared pitch to length or width since there is no particular reason to think that higher sounds are at the top and lower sounds are at the bottom however I specifically chose to compare pitch to height so that I could explain how we automatically assume that a slower vibrating sound is ‘lower’ while a faster vibrating sound is ‘higher’. The reason for the change in pitch is due to the vibration speed or frequency over time however we generally understand or express faster vibrations as being physically higher sounds and slower vibrations as lower sounds.
Sound is to hearing as what light is to sight and acoustics are to hearing as what reflection is to seeing. Both sight and hearing have a body part that is specifically used to perceive or capture sound or light. When we talk about ‘sound and acoustics’ we are referring to the space that surrounds a sound.
Imagine the space around an object as being a box with six faces (top, bottom, front, back, right, and left). The core of the sound exists in the center of the box, and any quality or event can exist or be measured before it, after it, above it, below it, and to it’s left and right sides through an imaginary ruler on each side. There are many other directions as well (ie. Diagonally), however the main goal here is to understand that an object, person, sound etc exists within a space and that it can be measured in many directions.
There are official names for each of these directions/measurements however for the purpose of explaining some basic elements of sound, we will simply focus on the most common measurements of Length, Width, and Height of the box. Now imagine that within this box/space, which can represent a theatre, a stage, or a room, lies another box which is sound itself. As is the case for the room, the sound can also be measured along it’s length, width and height … where the length can be the Amplitude, the width can be the Tone, and the height can be the Pitch.
Sound can therefore be broken down into smaller components/topics that could explain it from the bottom-up, back and forth, and side to side. Every one of these measurements (and more) make up a sound and it is important to understand these main parts to understand the bigger picture of why certain instruments are made a certain way, why a Soundman is needed at public events, and even whether you need that new amplifier or guitar pedal.
Sound is therefore a combination of elements that enter our auditory field (hearing), with a specific length, width and height … or in musical terms: a specific tone, pitch, and amplitude/volume. These qualities can be modified as the sound originates, or transmitted, as well as at perception. We will discuss this in more detail shortly however for now it’s simply important to understand that all sounds can be measured or broken down into various components/data elements.
