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Saturday, April 19th, 2014

Audible Range of Human Hearing – Acoustics of Music – Part 2

Audible Range of Human Hearing

Article Header BR1 Audible Range of Human Hearing   Acoustics of Music   Part 2

Scales in Music – A Tonal System

Acoustics of Music – Part 2

Audible Range of Human Hearing and the Influence of Loud Sounds

Welcome to Part 2 of the article series, Acoustics of Music and the audible range of human hearing article. There are two main reasons a person would want to limit both the range of frequencies and the level of amplitude or loudness when creating and listening to music. This foundation teaches us that there are specific limitations to consider when listening to music, making music, working in loud environments or when around or exposed to extremely loud noises over a protracted period of time.

The second consideration regarding audible range of human hearing and the influence of loud sounds is for understanding that there are limitations to our human ability to hear all sounds and noises. It is in understanding this limitation that we know we do not hear the complete sound spectrum, only that a portion of the sound spectrum falls into the audible range of human hearing.

Audible Range of Human Hearing – The average person has a normal hearing range that falls between 20Hz on the low side and approximately 20,000 Hz on the high side. As we age the overall perceivable range of sound decreases especially in the higher frequencies. Just in case you are wondering, hearing loss begins at around the age of 8 years old. It continues relative to the amount of abuse we put ourselves through. Our capability to hear sounds in the upper portion of the audible range of human hearing are for most people the first to go, as far as hearing loss is concerned.

The video below will give you a first hand experience of the limits of your own hearing capability. Please disregard the comments at the end of this video as they do not reflect my opinions. This just happens to be one of the better test examples especially in the upper frequency range where you can more closely identify the frequency at which you are unable to hear the sound. When you cannot hear the sound any more, this is your upper limit within the sound spectrum.

Caution – Please listen to this video with caution by setting your speaker or headphone volume to normal hearing levels for you. You may want to make adjustments as the video progresses so please keep your fingers on the volume control to protect your hearing. Thank you!

Surprising isn’t it? Most people never come to the realization that our own bodies limit our experiences of the universe and its limitless capabilities. It is for this reason that we must learn and understand the audible range of human hearing in order to protect ourselves and to create and design sound to fit within that range.  Again, based upon the amount of abuse we put ourselves through or are exposed to unwillingly, we live within a limited awareness of that unlimited universe.

Loudness or Amplitude – Science, specifically audiology, knows that the difference between the threshold of human hearing (0 dB) and the threshold of pain (120 dB) and hearing loss occurs at approximately 120 decibels. Loud sounds that are near 85dB can begin to cause hearing loss if experienced over prolonged periods of time.

Hearing Protection Audible Range of Human Hearing   Acoustics of Music   Part 2Due to the risks to the delicate nature of the tiny tissues and structures within the physical ear, those that make it possible for us to hear, we must do everything possible to limit long term exposure to loud noise and loud music in order to protect them. I would strongly urge that you wear hearing protection if you are exposed to loud sounds regularly. Also, listening to music within your comfort zone makes more sense than risking irreversible hearing loss thus limiting our own audible range of human hearing.

Loudness or amplitude is measured in decibels and it is marked or notated using dB to designate decibels. Keeping in mind that at 85 dB hearing loss can begin, normal everyday conversation is at approximately 70 dB and loud talking is about 90 dB. This is one of the reasons why loud and boisterous people bother us so much. How many of you know that a rock band can maintain about 110 decibels in volume? This is why after attending a concert your ears may ring or take a while to settle down afterward.

In reality, it is never a good idea to listen to extremely loud music for long periods of time without some sort of hearing protection. The consequences can be negative due to the sensitivities of the structures in our physical ear. It is by far more beneficial to limit the amplitude or loudness of the sounds we experience to within normal hearing ranges as much as possible, to limit the potential damage that may occur when listening to extremely loud sounds or music on a frequent basis. I’ll get down off my soap box now and thank you for listening.

The Human Ear Audible Range of Human Hearing   Acoustics of Music   Part 2

Frequency Limitations – Below is a chart comparing the range capabilities if various worldly creatures. The audible range of human hearing versus that of other living creatures is an interesting study. As the video exercise above proves the audible human hearing range is limited. This limitation is caused first by purely biological reasons and secondly by the damage caused by exposure to loud sounds. The chart includes the maximum range of audible and perceptible sound each species included in the chart is capable of hearing including the human species.

Hearing Chart Main Audible Range of Human Hearing   Acoustics of Music   Part 2

Frequency is measured using the Hz symbol meaning Hertz. The chart above shows a total span of frequencies from 20 Hz to 130,000 Hz. Noting that the limitation of the range of human hearing is between 20 Hz and 20,000 Hz one can easily see that frequencies exist outside of our capability to hear them. With that said, it is far more useful to write music within the audible range of human hearing. Due to things such as hearing loss, speaker limitations, musical instrument limitations and comfort zones, a range of frequencies more suitable for humans would fall between 20 Hz to 5,000 Hz and some would extend this range to a maximum of 7,500 Hz.

Although more frequencies are available to us in the overall perceivable sound spectrum it becomes to some degree non-useful to use all of the frequencies within the full audible range of human hearing when making music, although there are those who may attempt to do this.

A Finite System – These two limitations are why it is necessary to work within a finite system or finite range of sound. WE must always keep in mind the keeping the maximum amplitude limited to prevent hearing loss and to limited by choice the number of frequencies to only those frequencies which comprise the universally accepted frequency range of sound, as used in music and music composition and those that fall into the audible range of human hearing. It is therefore useful and appropriate to study the concept of acoustics and more specifically the concepts of frequency and amplitude as they are an underlying set of principals which are part of and necessary for completing your understanding of the components of another useful system herein called the musical scale.

Part 3 of the series Acoustics of Music included in the overall series Scales in Music – A Tonal System will provide some important information about acoustics and one of the key underlying principals in acoustics and the characteristics of sound. The concept is called frequency.

Please proceed with your reading of Part 3 which begins looking into these ideas about frequencies. It is titled; Acoustic Principals – Frequencies.

Mini Series Links

To return to the Music Theory – Level 1 directory for the article listings within the series, please proceed to Music Theory Section – Level 1 – Series Introduction – Part 10.

To continue onto Music Theory – Level 2 directory for the article listings within the series, please proceed to Music Theory Section – Level 2 – Series Introduction – Part 20

To proceed to Acoustics of Music directory for the listings within the mini-series, please proceed to Acoustics of Music – Part 1 – Series Introduction.

Valuable Resources

House Ear Institute – The House Ear Institute (HEI), a non-profit 501(c)(3) organization dedicated to advancing hearing science through research and education to improve quality of life.

National Hearing Conservation AssociationThe mission of the NHCA is to prevent hearing loss due to noise and other environmental factors in all sectors of society.

The American Academy of Audiology – is an excellent resource should you wish to research audiology, the study of hearing especially health conditions and injury.

The American Tinnitus Association - is another very excellent resource for those who may be suffering from this health condition. Tinnitus is a chronic and persistent ringing in the ears.

Audible Range of Human Hearing

 Audible Range of Human Hearing   Acoustics of Music   Part 2

About the author

Don Rath Jr wrote 112 articles on this blog.

Don Rath Jr is the President of StringTunes, an independent music publisher, and a contemporary instrumental music composer, arranger and guitarist. His music features the stringed instruments with a primary focus on guitar, string quartets and small group ensembles.

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