In many ways, humans are lucky the universe we live in allows for sound. Beyond facilitating things like communication and music, sound also permits several fascinating technologies that help improve our lives.
Today we’re going to go over some of the science of sound waves and how humans (and nature) have learned to take advantage.
How Do Sound Waves Work?
To understand sound, it may first help to know that there is no sound in the void of space. If you don’t understand how sound works, this may seem odd. After all, stars are, in essence, balls of constant explosive force.
The reason there is no sound in space is that there is (more or less) no air. Sound requires matter to travel through, vibrating particles that vibrate other particles, and so on. Without a medium to travel through, there is no sound.
Sound doesn’t only travel through the air either. In fact, sound tends to travel faster and farther through liquids and solids. The harder it is for one particle to vibrate another nearby, the less distance traveled by a sound.
One of the more important measurements of a sound is its frequency. Frequency, or pitch, is the number of times per second that the sound wave repeats itself.
A lower frequency sounds deeper and a high-frequency sound shriller. Lower frequencies travel farther than higher frequencies. We measure frequency in hertz (Hz), with a higher Hz level equaling a higher frequency.
A whole article (or even a book or series of books) could be written on specific properties of sound. For example, there is also amplitude for measuring volume. That said, we will keep it simple for now.
How Animals Hear
Sound carries a great deal of useful information. It can help signal when prey or predators are around. It can also allow us to exchange information with members of our (or a different) species.
Naturally (on a literal level, in this case), animals evolved to take advantage. Putting aside early evolutionary steps and edge cases, most animals now have ears that work somewhat the same.
We hear via our cochlea and the sensory cells therein. These hair cells detect vibrations that reach the ear. In turn, they send a signal to the brain, allowing animals to hear.
The human ear has a hearing range between 20 Hz and 20,000 Hz, but some animals can go beyond that. For example, bats use ultrasonic (very high frequency sound waves) sound for echolocation, accessing ranges you cannot hear.
While useful, the human ear can only do so much for us. The good news is that we have invented several machines to detect different frequencies for several beneficial reasons.
Humans have even learned to generate specific kinds of sounds for other purposes, like therapy. Acoustics, the branch of physics focused on sound, continues to deliver several advancements, and we’re sure to see more in the future.
When Invention Meets Sound
With the invention of key technologies, we now use sound in ways far beyond what the human ear allows for.
Today’s focus will be on medical technologies, but acoustic technology has helped everything from the music industry to the military. With that said, we will review only a few of the ways we have harnessed sound to our advantage:
One of the earliest examples of acoustic technology aiding in medicine, the concept of a hearing test is quite simple.
A patient wears a pair of headphones attached to a testing machine. They hold a button that is pressed whenever they hear a sound. An administrator then begins the test.
The machine will play a series of sounds meant to test the range of sound each ear of a patient can pick up. This allows for a far more precise diagnosis than a patient could tend to give themselves in terms of hearing loss.
To the modern reader, this technology may not be exciting, but it is still important. The device helps detect hearing loss, including loss over time, and help make sure the next technology we talk about is used to its fullest.
Hearing Aids and Cochlear Implants
Most people can hear a somewhat wide range of sounds with a fair degree of clarity. However, it is important not to paint in broad strokes—we must acknowledge those who cannot hear or otherwise have hearing damage.
Many people, through circumstances of birth, injury, disease, or several other factors, can experience partial or total hearing loss. While modern science cannot help all these people hear, it can help many of them.
The most common device used to help people with hearing loss is a hearing aid. This device is pretty simple in concept; it picks up sounds for the user and then repeats them at a higher volume, making them easier to hear.
More complex is the cochlear implant, which bypasses damaged or nonworking parts of the inner ear. This device helps to stimulate auditory cells with electricity.
Neither solution is perfect or works for all patients, but they help many people enjoy music and communicate when it was once impossible.
Ultrasound works, not unlike a bat’s echolocation. An ultrasound machine sends out an ultrasonic sound and then picks up the echo” of that sound as it bounces off of materials of different densities and at different distances.
This procedure (called a sonogram) is non-invasive and, in fact, poses no known risk to humans. While we tend to associate it with checking on the health of fetuses in the womb, it has other uses too.
Ultrasound can be used to check on many of the organs in our bodies, our circulatory systems, and more. Ultrasound is also combined with more invasive procedures, like biopsies, so that the work is more accurate and targeted.
Some people are under the impression a sonogram uses ionizing radiation, but this isn’t true. While ionizing radiation has some legitimate medical uses, it isn’t a part of a sonogram (nor related to acoustics).
At Oceanus America, we market a device that uses sound in a way we haven’t discussed so far. While we tend to think of sound as something used to hear, it can serve other purposes too.
Our Physio line utilizes a unique set of proprietary acoustic pressure waves that can target sites of pain or injury. These waves stimulate your metabolism, enhance blood circulation, and accelerate the healing process.
This works because sound waves don’t only allow us to hear. They also cause subtle vibrations on what they strike, a useful fact given time, precision, and careful study.
By adjusting a device to one of several protocols as best fits the condition being treated, sound helps heal injuries. A Shockwave therapy device can help with status post muscular injuries, patellar tendinitis, and more.
Some Physio devices are aimed at medical professionals, but there are also home models. Whether treatment requires an expert’s help depends on the nature of a given patient’s needs.
One of the fascinating ways acoustics may help in medicine is through what is called acoustic choreography. While it is a new technology with ways to go, it has shown a lot of promise.
Acoustic choreography is a process in which acoustics manipulate cells. In the case of researchers Dr. Sean Wu and Dr. Utkan Demirci, their focus has been on heart cells.
To cut through some nuance and complex science, it has been shown that heart cells can be guided to new positions and made to hold those positions with this technology.
Acoustic choreography can help with realistic cardiac disease modeling and drug screening. In the future, it may help form better heart patches and could heal damage from things like heart attacks.
Better Technology, Better Tools
Acoustic technology is an interesting field in that it is somewhat easy to see at least some of the ways it will improve in the future.
For one, the better we can get at targeting sound waves and picking them up as they bounce, the more precise imaging can get. In the future, imaging may be far more precise than we ever hoped.
Another area with promise is cochlear implants and similar devices. The more we learn about the brain, the better we can translate sound into signals it can understand.
In the future, even those born deaf may have the choice to hear. For the moment, however, many of those born deaf or who experience serious ear injury don’t have that choice.
Even our own Physio devices are likely to improve over time as we study the human body and further understand how sound can affect metabolism and blood circulation.
Acoustic Science Can’t Be Underestimated
Sound waves can do a great deal for humans and animals alike. Even better, the technology has plenty of places to go from where it stands now. We can expect great things from the field of acoustics in the future.
If you’re interested in Oceanus America’s technology, we hope you’ll contact us. We can answer questions about the products we offer and direct you to the options that best fit your needs!