Basic Characteristics of Sound
Basic Characteristics of Sound
In this information Age, the quest and journey for knowledge is something we all spend a lot of time doing. Well, I don’t know about you but sometimes I simply do not understand something when it is presented in only one way and so I search for other means to gain the understanding and knowledge I seek. As a result, I wander around scratching my head pondering and wondering, all the while not understanding what was being taught in that moment, until such time as new information comes along and all of a sudden the itch of wonder is replaced by knowledge and certainty.
Understanding sound and the basic characteristics of sound can be more easily learned in that same way. There are several concepts that are difficult to understand in music unless they are presented in more than one way too. Hopefully this article will help you to understand the basics of sound more fully by this multi-sensory approach. It is through an understanding of the characteristics that make up sound that you can more fully appreciate what you listen to, but more so, gain an understanding of some of the basic tools a composer considers and uses when creating a piece of music.
After all, music is actually and simply sound and sound has only four basic characteristics. When we arrange these characteristics in such a way that we find it pleasing to listen to we call that music.
Fundamentals of Music and the Characteristics of Sound
The basic characteristics of sound and the fundamentals of music are by their very nature a necessary tools to use in many of the future papers I will be presenting over time. The basic characteristics of sound consist of only four fundamentals; pitch, duration, quality and intensity, however, the character of the sequence of sounds and its arrangement is what makes music subjectively pleasing and individually enjoyed. Let’s take a closer look at these four basic characteristics of sound that comprise the very foundation for everything else we will be discussing, as related to music.
Characteristics of Sound – Pitch* – Pitch is the first of the characteristics of sound we will review in this article. In music notation, pitch can be seen visually by looking at the placement of a note on a musical staff. By comparing the location of where two or more notes are placed graphically, we look at their relative position to one another and we know in what direction they are related to each other, in a position of either higher or lower than another. We can make a comparison of the two notes thereby easily identifying where each note is located spatially on the staff by making a visual distinction. This is made possible through the use of notation software or by notating music by hand. The example below shows visually the basic concept of pitch.
Each sound or tone represented by the notes in the above diagram can be produced using a musical instrument. This transforms our visual only presentation (the notes as they appear on the notation chart) into an audio presentation, what we hear when played by an instrument. When both the visual and audio are performed by a musician we call this “sight reading” of music. Again, the notes are relative to each other, higher or lower, and we understand their relationship by making the visual comparison of one to the other. We can see pitch visually in this way and at the same time hear the sound in an analog or auditory way by playing the notes on an instrument or we can do the same thing by playing a sound clip at the same time we look at the chart below. So, before playing the notes first look at the chart and make some distinctions such as, the first note is lower than the second note which is located higher on the chart. Then click on the link and listen to the sound, paying attention to and identifying the differences between the two notes being played.
In essence, we have two methods of determining pitch using our senses, sight and hearing. We will limit our understanding to these two senses at this time, unless you are so inclined to pull out your musical instrument and play the notes now if you wish. By doing this you can experience the notes in three senses; hearing, sight and tactile feeling. However, it is important to know that through a multiple sensory approach such as this we can learn to associate the sound of the note on the staff and in reverse hear the note, randomly name it when played and learn how to notate music that is rolling around in your head. We can also learn to sing from this basis too.
Characteristics of Sound – Duration – Duration is the second basic characteristics of sound. It is also a simple concept whereby we make additional distinctions based upon the linear structure we call time. In music, the duration is determined by the moment the tone becomes audible until the moment the sound falls outside of our ability to hear it or it simply stops. In music notation, a half note is longer than an eighth note, a quarter note is shorter in duration than a whole note, for example.
As shown in the following chart, visually, we see notes represented by different note shapes. These shapes determine the designated amount of time they are to be played. Silence is also represented in the chart by the funny little shapes in between the notes. They are called rests and this is also heard as silence and they too exist only for the designated time associated to the rest’s shape. Note shapes partially determine the duration of the audible sound and rest shapes partially determine the duration of silence in music. We will see in a minute how this can vary.
By playing the sound clip you can hear the difference between the tones in terms of duration, longer or shorter. We can also hear the difference in the length of the silence, again, longer or shorter. Remember, we are comparing one note to the other or one rest to the other.
After your visual review, please click on the link below the chart to hear the sound clip. Also, if you click on the little box instead of the underlined words you can see and listen together, otherwise, if you click on the words then you will be in listen only mode.
Here’s another example of duration.
The notation above shows some newly presented note lengths/shapes following the eighth note in the second measure. These are sixteenth notes. Using the vibrato legato sound samples to demonstrate this aurally they sound all bunched together versus the prolonged half note for example. This is another way that composers and performers can create interesting sounds by combining different note durations and performance techniques such as the vibrato legato as used in these two audio clips.
Characteristics of Sound – Quality – Quality is our third basic characteristic of sound. From a church bell tower we hear the sound of the large bell ringing in the neighborhood. Assuming the bell is playing a C note and we compare a different instrument playing the same C note, a tuba for example, we can make the comparison between them listening and comparing the tonal qualities or timber differences between the two instruments. The pitch of the notes is the same. This exercise will help in understanding tonal quality. Even though the pitch is the same for both notes they sound different, in many ways.
To further explain; below is an mp3 sample of two different instruments, one following the other. One instrument is a violin and the other is a flute, both playing the same C note or the same pitch. The difference we hear is not in duration or in pitch but in tonal quality or timbre. This aspect of music is broad and encompassing of the many different possibilities available from different instruments and from the same instrument as well. The skill and artistry of the performer also plays a significant role and highly influences the tonal quality produced by a single instrument as does the quality and character of the instrument itself.
I have used two different tones, the C and the G notes (that’s the one in the middle), to demonstrate the tonal characteristics by comparing the sound qualities between a flute and a violin. The last measure provides a comparison again, but this time while both instruments are simultaneously sounding. When both sound at the same time is also called playing in unison. Even though the sounds have a unique tonal quality the instruments cause a variation in the actual sound we hear from each instrument.
All sounds that we hear are made up of many overtones in addition to a fundamental tone, unless the tone is a pure tone produced by a tuning fork or an electronic device. So, in music when a cellist plays a note we not only hear the note as a fundamental note but we also hear the overtones at the same time. By making sounds from different instruments and sounding them simultaneously we hear a collection of tonal qualities that is broader in scope however, again we still primarily hear the loudest or the fundamental tone. The spectral analysis and 3-D photos below can visually demonstrate this point.
Spectral Analysis
Each peak is not simply a vertical line. It has many more nuances and sounds making up the total sound we hear. The photo shows this where in between each peak we see a lot of smaller peaks and the width of the main peaks is broad, partly contingent upon intensity and partly on overtones.
Note: Tonal quality and overtones can be further understood visually by taking a closer look at the first picture in this article. It is reproduced here for convenience.
Visually, this 3d sound spectrum clearly demonstrates that sound as we normally hear it is comprised of a collection of sounds and not a pure tone. The various high peaks represent what I would call primary and secondary overtones and the highest would be the fundamental.
The concept of and study of overtones and other sound mechanisms takes us to material and information far beyond the scope of this article, it is by the way an interesting study. Our intention here is to provide the basic understanding of the difference in tonal quality as compared to intensity, duration and pitch.
Characteristics of Sound – Intensity – Our fourth basic characteristics of sound is called Intensity. It is a measure of the loudness of the tone. Assuming that the pitch, duration and tonal qualities are the same, we compare two or more tones based upon loudness or intensity. One is louder or quieter than the other. When playing a piano for instance, if we strike the keys gently we produce a very quiet sound. If we strike them hard we produce a much louder sound even though the pitch is the same. Here is an audio clip comparing intensity or loudness on the flute. The pp is very quiet and the fff is very loud.
Intensity can also be seen when working with a wave form editor as the photo below shows. The larger the wave form the louder the sound. If you’ll notice the small “wavy line” in between each of the larger wave forms in this snapshot, even though they show up on the graph, it is likely that you do not hear the sound in these locations as the loudness is below the human range of hearing.
The really super cool thing about working with wave forms is that you can edit them extensively and make unique sounds out of the originally recorded instrument. That method of editing sound is only one of the ways in which digital sound can be manipulated and controlled.
In conclusion, the four basic characteristics of sound; pitch, duration, quality and intensity collectively can be observed in all sounds from any source including those made by musical instruments. No single sound characteristic can be divorced from the others and neither is more important than the other. Collectively they make up the basic characteristics of sound whether it is consciously heard or not. Without exception, each characteristic is continuously influencing the others and each is simultaneously being influenced by the others. How well the composer and the performer knows and understands how to use sound characteristics in their work will be an influencing factor in how well received their music is by their audience.
More Information – If you have enjoyed your review of this article please check out the article series – Scales in Music – A Tonal System – Acoustics of Music.
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For a more technical perspective on pitch please refer to this excellent article from the Laboratory of Dale Purves, M.D. at the Duke University Center for Cognitive Neuroscience.
Here is the link written out – http://www.purveslab.net/research/explanation/sound/sound.html
Article Note: The photos above were produced using two different software programs; Sibelius 6 a product of Avid Technologies and WaveLab 6 a product of Steinberg.
Basic Characteristics of Sound
