There are a lot of sounds surrounding us.
Hearing them helps us understand our environment.
These sounds may be pleasant to be heard, or they may create agitation in our minds.
The human ear can hear a certain level of sound, or you can say that there is a specific range of frequency of sound waves that our ears can hear and handle.
In this article, we will discuss sound frequency, the difference between high and low-frequency sound, and its effect on our ears.
What is sound?
Sound travels in waves.
The sounds we hear are of various kinds.
Some sounds are shrieking; some are soothing.
Some are pleasant, and some are horrible things to us.
This is all due to their different characteristics.
The wavelengths of the sound determine the nature of the sound we hear.
Also, sound waves, such as air or water, need a travel medium.
Because sound waves make oscillations in that medium’s particles, and thus sound travels from one place to another.
So we can say that sound travels through a medium such as air or water in the form of waves.
It is measured with its frequency and amplitude.
Frequency of the sound waves
The number of times per second a sound wave repeats itself is called the frequency of sound waves.
This is also known as the pitch of the sound.
The higher number of oscillations refers to the higher frequency of sound, and the lower number refers to the lower frequency of sound.
The unit of measurement for the frequency of sound is called Hertz (Hz).
A normal human ear can listen to sounds falling in the frequency between 20Hz to 20,000Hz.
All other sounds go unheard by the human ear.
Differences between different sounds can be made because their frequencies don’t match.
For example, a drum beating has less frequency than a whistle.
What is the amplitude of sound?
Amplitude refers to the loudness or volume of the sound.
It is measured in decibels (dB).
It is the intensity of the sound or the pressure level created by the sound waves.
Normal sounds like speaking of a person who is under 60 decibels.
While some louder sounds, for example, the sound of a vacuum cleaner, sound almost equal to 70 dB.
Wherever the amplitude rises to 85 dB, a hearing aid should be used; otherwise, it is not healthy for the human ear.
What is noise?
Noise is sometimes considered a synonym for sound, but it is false.
Noise is the unwanted and annoying sounds that fall in the category of either high-pitched sounds or sounds with high amplitude; for example, in a mall or in a park where people are speaking altogether and thus creating too much noise.
What is meant by low frequency and high frequency of sound?
Now, as we have reviewed the basic terminologies of sound, we can open the basic idea we are going to discuss.
As we discussed earlier, the human ear can only listen to sounds falling in between the frequency of 20 to 20000 Hz.
So the frequency of the sound waves is important to understand regarding listening and hearing.
Some words about different sound frequencies
So, now we know that audible sounds are dependent on their frequencies. That’s why knowing more about different sound frequency ranges is important.
According to frequency, sound waves can be categorized into three categories. Let’s have a look at their details.
● Low-frequency sound waves
Low-frequency sound waves fall in the range of 500Hz or below.
The frequency of sound waves is inversely proportional to the wavelength of the sound waves.
It means that the greater the wavelength of the sound, the lesser the frequency of sound waves.
Low-frequency sound travels greater distances and passes through walls easily.
A normal human ear cannot hear sounds with as low frequency as 20Hz or low.
It is rather easier to feel them. Like, the bass created by the music system speakers creates vibration, and you can feel them.
● Middle-frequency sound waves
Middle-frequency sound waves are sound waves which fall in the range of 300 Hz to 2000 Hz.
This is the normal range of the sound wave frequency because most of the sounds we hear daily belong to this sound frequency category.
They provide most of the information to us because we clearly can listen to them.
High and low-pitch sounds help these middle-pitched sounds to be more clear.
● High-frequency sound waves
Sound waves having a frequency above 2000 Hz are considered high-frequency sound waves.
These high-frequency sounds add presence and clarity to the noise.
A person’s voice belongs to the middle-frequency sound range.
All the other unwanted noise mostly belongs to this category.
Sirens, bus horns, and fans humming also belong to this category.
As mentioned before, high-frequency sound waves mean shorter wavelengths.
That’s why it mostly fades out when these waves travel through a dense surface or a greater distance.
So, we can say that we can listen to them only if we are present near them.
Loud, shrieking noises mostly fall in this category.
It would be worthwhile to mention here that while recording different musical instruments, by adding more bass to the sound waves, we try to filter the high-frequency sound and convert them to low-frequency sound waves.
Thus creating a soothing impact of music on the listeners.
Impact of different frequency sounds
Different frequency sounds have a different impact when it comes to figuring out whether they’ll pass by or they’ll be absorbed.
High frequency, meaning high-pitched sound, has a smaller wavelength, so more chances are they will fade out.
During low frequency, low-pitched sound has a greater wavelength, so they’ll probably travel more.
Now we’ll discuss the impact of different sound frequencies and how to control them.
The sound that passes through a surface
This belongs to the latter category mentioned above.
They are low-frequency, low-pitched sounds that have a greater wavelength.
Due to greater wavelength, the chances of the sound waves fading out becomes less. It can travel a greater distance.
Sound waves travel through the air.
Sound waves can also pass walls and bricks-like materials.
But it depends upon the density of the material. More dense and thicker material means fewer chances of noise and sound passing through it.
For this matter, sound energy-absorbing materials should be used.
They absorb the sound energy, and thus sound doesn’t pass through such materials.
The sound that is reflected by a surface
Sound waves travel through the air and will continue to do so until some surface creates a barrier in its way, and it will bounce back.
When the sound bounces back, it creates echoes.
Echos are divergent sounds and are difficult to interpret sometimes.
This problem can be solved by using sound-absorbing materials in the buildings.
Sound-absorbing materials are mostly soft and porous, so sound waves can easily be absorbed in them.
The sound that creates vibration
Whenever the loud or shrieking sound or noise touches some hollow surface, it mostly creates a vibration on that surface.
It ultimately leads to more noise and louder sensations.
Sound-dampening materials can be used to solve the problem.
They absorb the sound waves. Thus reducing the problem of echo and vibration.
Sound crossing the holes and cracks
Sound escaping through the holes and cracks in the walls and door corners is another problem.
This is a bigger problem because sound travels through such cracks regardless of the frequency.
This problem can only be solved by taking care to fill these gaps with some good sound-absorbing material.
Best materials to stop them from passing through
Whenever you have to solve the noise problem, you can use many soundproofing materials available in the market.
Some of them we can discuss here.
Vinyl sheets are the best option for sound dampening.
When used in your home or office, they add to the mass and surface density.
It will then not reflect sound.
Instead, it will absorb all noise and will help reduce noise.
It can also be used between the layers of drywall, enhancing its absorption capabilities.
Green glue sealant is very effective for soundproofing.
Whenever acoustic panels are used in infrastructure, the finishing should be done with green glue.
It’s very effective.
On top of that, it is non-toxic and creates a dampening effect as well. It can also be filled between two layers of drywall.
Sounds surrounding us are of various kinds.
They vary in properties like frequency of sound waves, pitch, loudness, etc.
We were particularly discussing here the difference between low-frequency and high-frequency sounds.
There is a certain range of the sound wave’s frequency that a normal human ear is capable of listening to.
Sounds below or above this range go unnoticed by us.
The soundproofing methods can tackle the noise level that is created by loud, high-pitched sounds.
Above discussed solutions can prove to be a great help in this regard.
Frequently Asked Questions
1) How do high and low-frequency sounds differ in wavelength?
High frequency sound waves have a shorter wavelength than low-frequency sound waves.
This means that high-frequency sounds have more waves per unit of distance than low-frequency sounds.
2) What are some examples of high-frequency sounds?
Some examples of high-frequency sounds include the sound of a whistle, a bird chirping, or a person screaming.
3) What are some examples of low-frequency sounds?
Some examples of low-frequency sounds include the sound of thunder, a bass guitar, or an earthquake.
4) How do high and low-frequency sounds affect our hearing differently?
High frequency sounds can be more damaging to our hearing than low-frequency sounds, as they can cause more damage to the delicate hair cells in the inner ear.
Low-frequency sounds, on the other hand, can often be felt more than heard, and can cause vibrations in the body.
5) What are some practical applications of understanding the difference between high and low-frequency sounds?
Understanding the difference between high and low-frequency sounds can be useful in a variety of fields, from audio engineering to medicine.
For example, doctors may use high-frequency sound waves for imaging purposes, while audio engineers may use low-frequency sound waves to create a bass-heavy mix.