Browse by Application
Browse by Application
Browse by Product Type
Browse by Product Type
Exploring the Limits: What Frequency Can Humans Hear?
Listen carefully on a still, clear night and you’ll be amazed at all the sounds you can hear. From the whir of electrical boxes to the woosh of distant traffic and the woofs of neighborhood dogs, the human ear can pick up a fairly wide range of noises.
Frequency, also called pitch, is one way of measuring the potential range of human hearing. From the bassy calls of baboons to the high pitched whistles of songbirds and noises we can’t even hear, all frequencies are measured in hertz (Hz) and the scale far exceeds the capabilities of the human ear.
So, that begs the question: what frequency can humans hear?
Well, our ears are all different, but general ranges do exist and, in this guide, we’ll shed some light on the minimums and maximums of human hearing and detail different soundproofing techniques to combat various frequencies.
Understanding the Human Ear’s Hearing Range
Sound travels through different mediums—most often air, but also water and solid materials—in the form of waves. In order to measure and accurately track these waves’ movements, humans rely on the aforementioned frequency scale. Frequency is a measure of how many times soundwaves repeat themselves in a single second. Lower frequencies have fewer sound wave oscillations (i.e. repetitions), resulting in low-pitched, bassy sounds. Meanwhile, higher-frequency sound waves oscillate more quickly, creating high pitched, squeakier noises. More or less, the average human ear can hear sounds ranging from 20 Hz to 20,000 Hz (also known as 20 kilohertz or 20 kHz). Our abilities to pick up on certain sounds, however, vary from person to person based on factors like:- Deafness and hard of hearing status – The World Health Organization (WHO) reports that over 5% of the world’s population—or roughly 430 million people—have disabling hearing loss that requires rehabilitation. On top of this, countless more are suffering from other forms of acute ear damage that limit their hearing potential. In such cases, affected individuals generally can’t register as wide of a range of frequencies as those not dealing with hearing loss.
- Musical training – Scientific research has shown that children with robust musical training can detect and discern frequencies that untrained ears may not. They’ve also been shown to identify pitch changes with greater accuracy than individuals who don’t boast a musical background.
- Genetic ability – Just like some people are born supertasters and can identify a larger spectrum of flavors than most people, some of us are born superhearers. These “golden-eared” individuals may be able to hear higher or lower frequency pitches than the average person.
The Science Behind 20 Hz to 20 kHz
The 20 Hz to 20 kHz range is actually the spectrum of sound that adult humans can usually hear. When we’re babies, we’re generally capable of hearing sounds slightly above 20kHz. As we get older, however, the loud noises we encounter over the course of everyday life slowly wear away at our hearing abilities. Eventually, this persistent damage lowers our frequency cap to 20 kHz. This is just a general limit, however, and it’s not uncommon for adults to actually only register sounds up to 15 to 17 kHz. The WHO also warns that modern-day headphone usage—amongst other factors—is accelerating hearing loss and, in the future, more and more individuals may have lower maximum frequency thresholds. 20 Hz to 20 kHz is just the average human range for hearing, however, and the spectrum goes far beyond these limits. Plenty of other animals can hear frequencies that simply blow past our ears. That’s why dogs are set off by seemingly soundless whistles and humans need special microphones to hear the deep songs of blue whales. Some sounds sit on the very borders of what we can barely register and what other animals hear constantly. On the normal edges of human hearing, there are two types of noise:- Sub-bass sounds – From around 20 to 60 Hz sits the sub-bass range of the sound spectrum. These are the deepest noises most humans can register and, oftentimes, you may feel them more so than hear them. Think of the bassy kick of deep electronic music being played over a high end sound system. You can often feel the reverberations in your body and bones more clearly than you can hear sound pumping out of the speakers.
- Ultrasonic frequencies – Any sounds above the normal hearing threshold of 20 kHz are considered ultrasonic frequencies. While we might not necessarily be able to hear such noises directly, that doesn’t mean they don’t affect us. Medical authorities warn that prolonged exposure to high decibel ultrasonic frequencies can expedite hearing loss and lead to symptoms such as tinnitus, dizziness, headaches, fatigue, and nausea.
How to Test Your Personal Hearing Range
The best way to determine your own personal hearing range is to have it assessed by an audiologist or Ear, Nose, and Throat doctor (ENT). They’ll most accurately be able to assess your potential range and determine if you’re suffering from hearing loss or other ear damage. Besides getting a professional medical opinion, there are also other ways to assess your hearing capabilities from the comfort of your own home. Anonline hearing test can gauge your frequency range in about five minutes and, while their results won’t be as accurate as an audiologist or ENT, they’re a solid starting point for understanding your capabilities Keep in mind your own speakers’ limitations when taking an online hearing test. Many computer speakers and entry-level subwoofers struggle to produce sounds below 40 Hz—so, even if the test says it’s judging your ability to hear 20 Hz, that may not necessarily be the case.Soundproofing and Human Hearing
Extended exposure to high or low frequency sounds—or even those in the middle of the spectrum, if the volume’s loud enough—can cause permanent, irreparable damage to our ears. That’s why, as previously mentioned, our frequency caps are above 20 kHz as babies, but fall as we grow older. In order to protect our ears against this damage, it’s pertinent to soundproof our homes, workplaces, and other spaces with the potential for ruckus. Soundproofing and sound absorbing materials work in different ways. They may reflect sound back toward its source, keeping it contained to a certain room so it doesn’t leak out into adjacent spaces. Or, they may absorb noise as it travels through walls and other partitions—effectively filtering out the audible frequencies, reducing its volume, and making it unregistrable. Which type of material you’ll use depends on the exact application and whether you’re trying to mitigate high or low frequency noise.Soundproofing Solutions for Different Frequencies
Low frequency noise consists of long, slowly reverberating waves that have a tendency to pass right through solid surfaces. Sounds under 100 Hz can rattle walls, floors, and ceilings—as anyone who’s lived in a busy city or large apartment building can tell you. Bassy sounds are notorious for their ability to travel, but how can you mitigate their effects on your home or workplace? With one word: mass. The heavier and thicker the surface, the more difficult it is for low pitch sound waves to travel through. Thus, to block out low frequency noise intrusion, the best tool in your arsenal is a Soundproof Mass-Loaded Vinyl Sound Barrier. Noise S.T.O.P.™ Vinyl Barriers are made of high density vinyl foam up to one-quarter of an inch thick. They can be mounted to floors, walls, or ceilings to filter out the annoyance of low frequency sound waves pushing through from the other side. Simply tack them up with a few nails, screws, or staples to instantly dampen exterior noise and regain a sense of peace in your space. When it comes to sound issues, however, low frequency noises are only half the battle. Luckily, high frequency sound waves are more easily absorbed than those lower on the spectrum, so mass-loaded vinyl is a solid solution for them as well. Generally, however, you’re not only dealing with one sound frequency and, oftentimes, noise barriers alone may not be enough to block everything out. You see, sound in a space is a lot like water in a fish tank: if there’s a hole, it will find it and continue leaking out until it’s plugged. So, to protect your domain from both low and high frequencies, you should utilize a variety of acoustic sound barriers, including:- Green Glue Viscoelastic Damping Compound to seal up any cracks or gaps in your floors and walls
- Acoustic Underlayment beneath your flooring to prevent noise from downstairs neighbors creeping through their ceiling
- Acoustic Barrier Ceiling Tiles in place of standard drop ceilings to maximize sound absorption in spaces where you can’t mount mass-loaded vinyl directly above