How Does Passive Noise Cancelling Work? Ultimate Beginners Guide

How Does Passive Noise Cancelling Work- Ultimate Beginners Guide
  • Post last modified:August 13, 2023

You Know What’s Passive Noise Cancelling and how does it work? In our guide to “How Does Passive Noise Cancelling Work“, we will everything you need to know as a beginner.

So, you must have heard about noise cancelling! If not, we welcome to the world of noise reduction technology!

Passive noise cancelling is a great innovation designed to reduce or even eliminate unwanted noise by physically blocking sound waves.

Unlike its counterpart, active noise cancelling, which employs electronic circuits to create anti-noise for countering incoming sound waves, passive noise cancelling operates without the need for any power source.

The working mechanism of passive noise cancelling involves using specialized materials or structures that act as barriers to sound waves, preventing them from passing through.

This results in a quieter and more serene environment, especially in places with high ambient noise.

The applications of passive noise cancelling are diverse and widespread. You can find it incorporated in various products like headphones, earmuffs, and architectural designs for soundproofing rooms.

Its versatility makes it an ideal choice for anyone seeking peace and tranquillity in noisy surroundings.

One of the significant advantages of passive noise cancelling over its active counterpart is its simplicity and lack of dependency on electronics.

It doesn’t require batteries or charging, making it hassle-free and always ready for use. Passive noise cancelling also tends to be more budget-friendly, making it accessible to a broader audience.

So, passive noise cancelling stands as a remarkable technology, reducing or eliminating unwanted noise through physical barriers.

With its numerous applications and the ease of implementation, it has rightfully earned its place as an excellent choice for those looking to enjoy a quieter and more enjoyable environment.

I know you are more anxious to know more about passive noise cancelling now!

If you’re someone who frequently travels or finds themselves in noisy environments, you must be familiar with noise-cancelling headphones.

These incredible gadgets utilize advanced technology to minimize background noise, allowing you to fully immerse yourself in your music or concentrate on work without any disturbances.

Among the various types of noise-cancelling technology, there’s passive noise-cancelling, which offers an ingenious solution without the need for any electronic circuitry or power source.

Passive noise-cancelling headphones are designed to reduce unwanted noise solely through physical means.

How does it achieve this?

The magic lies in the materials used, such as foam, rubber, or leather, which form a snug seal around your ears when you wear the headphones.

This seal acts as a barrier that effectively blocks or muffles incoming sound waves, preventing them from reaching your ears and disrupting your listening experience or concentration.

Without relying on batteries or electronic components, passive noise-cancelling headphones prove to be remarkably simple and hassle-free to use.

They are particularly beneficial for those who prefer a more straightforward and environmentally-friendly option.

In this article, we’ll delve deeper into the world of passive noise-cancelling technology, exploring how it functions.

We will also look at why it serves as an excellent choice for creating a peaceful and focused auditory environment.

So, let’s embark on this noise-cancelling journey together!

Importance of noise cancelling in daily life

Whether you’re studying, working, or simply seeking some peaceful moments, noise cancelling proves to be an invaluable tool.

It helps concentration by effectively blocking out distracting background noise. This becomes especially essential in noisy environments like open-plan offices or during commutes on public transport.

The adverse effects of noise pollution on our mental well-being cannot be ignored. Noise cancelling technology acts as a welcome escape, creating a more serene and tranquil environment.

By reducing stress levels and promoting relaxation, it becomes a powerful ally in combating the constant barrage of external sounds.

Furthermore, noise cancelling can significantly improve the quality of our sleep. Particularly beneficial for those residing in noisy areas.

It acts as a shield against disruptive sounds like traffic or construction, allowing for a more restful and rejuvenating slumber.

Beyond its immediate benefits, noise cancelling plays a crucial role in protecting our hearing health over the long term.

Continuous exposure to loud noises can lead to hearing damage, but noise cancelling devices mitigate this risk.

By reducing the need to crank up the volume to drown out external sounds, they safeguard our precious ears from potential harm.

Moreover, noise cancelling adds to the joy of listening to music or audio. By reducing or eliminating background noise, it allows audiophiles to immerse themselves in an unparalleled sonic experience.

Therefore, noise cancelling is a powerful technology with a many of advantages.

From enhancing focus and concentration to providing stress relief and protecting our hearing, it enriches our daily lives in countless ways.

So, whether you’re seeking a peaceful study session, a stress-free commute, or an elevated music-listening experience, noise cancelling is here to elevate the quality of your life.

Difference between active and passive noise cancelling

Active and passive noise cancelling technology works to cancel out the noise. But these are a little different from each other.

  • Passive Noise Cancelling

Passive noise cancelling takes a more straightforward approach. It achieves noise reduction by physically blocking out unwanted sounds rather than generating an opposite sound wave.

The use of specialized materials like foam or rubber aids in absorbing the sound waves, leading to effective noise reduction.

However, it’s worth noting that passive noise cancelling is most effective against low-frequency noise, making it an excellent choice for situations like dulling the hum of an airplane engine.

  • Active Noise Cancelling

On the other hand, active noise cancelling represents a more advanced and versatile technology.

This method tackles noise across all frequencies by employing microphones to detect external sounds.

Once detected, it creates an opposite sound wave to counteract the incoming noise, effectively cancelling it out.

Active noise cancelling is commonly found in headphones and is particularly adept at reducing sounds like engine noises or other continuous background disturbances.

Having all that said, passive noise cancelling offers a simpler approach that is ideal for specific noise types.

But active noise cancelling showcases a more sophisticated technology that can handle a broader range of sounds.

Depending on your needs and preferences, both methods have their unique advantages and applications in providing a quieter and more peaceful auditory experience.

Understanding the Basics of Sound Waves


Since we are trying to understand noise canelling technology and how it works, it’s a sensible idea to throw some light on the basics of sound waves.

Definition of sound waves

Now let’s talk about sound waves. This a remarkable form of wave that transmits energy through vibrations in various mediums like air or water.

These vibrations bring about changes in pressure, which our human ears perceive as sound. The journey of sound waves can span significant distances.

So, their unique frequencies and amplitudes dictate both their pitch and volume.

As these waves propagate through the medium, they create oscillations that travel through the air or water, carrying the energy of sound.

When these oscillations reach our ears, they cause our eardrums to vibrate, and these vibrations are then translated into the auditory experience that we recognize as sound.

The frequency of a sound wave refers to the number of oscillations it completes per second, and this directly influences the pitch of the sound.

Higher frequencies result in higher-pitched sounds, while lower frequencies produce deeper tones.

On the other hand, the amplitude of a sound wave determines its volume. Greater amplitude corresponds to a more powerful wave.

So that it creates a louder sound, whereas smaller amplitudes result in softer and more gentle sounds.

Therefore, sound waves are incredible phenomena that traverse through mediums, captivating our senses and allowing us to experience the diverse range of sounds in the world around us.

Understanding their characteristics, such as frequency and amplitude, enhances our appreciation for the beauty and complexity of the auditory universe.

Properties of sound waves

Sound waves have several properties, including frequency, wavelength, amplitude, and speed. Frequency determines the pitch of the sound, while wavelength determines its spatial extent.

Amplitude determines the volume or loudness of the sound.

The speed of sound waves varies depending on the medium they travel through. Sound waves can also be reflected, refracted, and diffracted.

  1. Frequency: The frequency of a sound wave determines its pitch. It refers to the number of oscillations or vibrations the wave completes per second.

Higher frequencies result in higher-pitched sounds, while lower frequencies create deeper tones.

  1. Wavelength: Wavelength corresponds to the spatial extent of a sound wave. It represents the distance between two consecutive points of similar phase in the wave.

Shorter wavelengths are associated with higher frequencies, and longer wavelengths are linked to lower frequencies.

  1. Amplitude: The amplitude of a sound wave dictates its volume or loudness. It measures the maximum displacement of particles in the medium as the wave passes through.

Greater amplitude results in louder sounds, while smaller amplitude leads to softer sounds.

  1. Speed: The speed of sound waves is influenced by the medium they travel through.

In general, sound waves travel faster in denser materials. For example, sound travels faster in solids than in liquids, and faster in liquids than in gases.

The interplay of these properties allows us to perceive the rich array of sounds that surround us.

But the journey of sound waves doesn’t end there. Sound waves can encounter various phenomena, including:

  1. Reflection: Sound waves can bounce off surfaces when they encounter obstacles.

This reflection of sound allows us to hear echoes and contributes to the sense of space in various environments.

  1. Refraction: When sound waves pass through a medium with different properties, such as transitioning from air to water, they can change direction due to a change in speed.

This phenomenon is known as refraction.

  1. Diffraction: Sound waves can also bend or spread out when they encounter obstacles or pass through openings.

This diffraction allows sound to reach areas that might be hidden from direct line-of-sight, enabling us to hear sounds around corners or behind barriers.

Indeed, sound waves are complex and versatile entities with distinct properties like frequency, wavelength, amplitude, and speed.

They interact with the surrounding environment, allowing us to experience the beauty and intricacy of sound in various captivating ways.

Understanding these properties and phenomena enriches our appreciation of the wondrous world of sound.

How sound travels

Sound waves, the fascinating carriers of sound, traverse through various mediums like air, water, or solids, by initiating pressure waves that propagate through the molecules of the medium.

This journey begins when an object vibrates, creating disturbances in the surrounding air molecules.

These initial vibrations cause adjacent molecules to vibrate in a chain reaction, effectively transferring the sound energy through the medium.

As the sound waves propagate, they create alternating high and low pressure regions, generating compressions and rarefactions.

Our ears detect these pressure fluctuations, and our brains interpret them as the sounds we perceive.

The speed of sound waves is dependent on both the medium they travel through and their own frequency and wavelength.

In general, sound waves travel faster through denser materials like solids than through less dense ones like air or water.

Also, the frequency and wavelength of the sound waves also play a role in determining their speed.

The amplitude of a sound wave has multiple effects on the sound we hear.

Firstly, it influences the pitch of the sound, with larger amplitudes corresponding to higher pitches and smaller amplitudes resulting in lower pitches.

Secondly, it determines the spatial extent of the sound wave, with higher amplitudes leading to stronger pressure variations over a larger area.

Finally, amplitude directly impacts the volume or loudness of the sound, with greater amplitudes resulting in louder sounds and smaller amplitudes leading to softer sounds.

Types of Noise

Here are some examples of different types of noise:

  1. Environmental noise: Traffic, construction, airplanes, trains, and sirens.
  2. Industrial noise: Heavy machinery, equipment, compressors, generators, and drills.
  3. Occupational noise: Construction sites, factories, music venues, and airports.
  4. Electrical noise: Hum or buzz from electronics such as computers, televisions, and electrical appliances.
  5. White noise: A steady sound that sounds like static, often used to mask other sounds.
  6. Pink noise: A sound that is similar to white noise but with more energy at lower frequencies, often used in sound therapy.

Brown noise: A sound that is similar to pink noise but with more energy at even lower frequencies, often used in sound therapy and relaxation.

How noise affects our daily lives

Noise affects our daily lives by causing physical and mental health issues, such as hearing loss, sleep disturbances, stress, anxiety, and decreased cognitive performance.

It can also decrease productivity and increase aggression, impacting our overall quality of life.

What is Passive Noise Cancelling?

Let’s understand what is passive noise cancelling

Definition of passive noise cancelling

Passive noise cancelling is a technique used to reduce the amount of external noise. This noise reaches the listener’s ears without the use of any electronic components.

This technique works by physically blocking the sound waves from reaching the ear. This is achieved through the use of materials that absorb, reflect, or scatter the incoming sound waves.

Passive noise cancelling is commonly used in the design of noise-reducing headphones. This is also used in earplugs and acoustic panels.

While it may not completely eliminate the external noise, it can significantly reduce the noise level. Thus, lets the listener hear only the desired audio without any disturbance.

How passive noise cancelling works

Passive noise cancelling works by physically blocking external noise from reaching the listener’s ear. This is achieved through the use of materials that absorb, reflect, or scatter incoming sound waves.

For example, noise-reducing headphones use thick padding to block out external noise. Earplugs use materials such as foam to fit inside the ear canal, creating a seal that blocks out noise.

Acoustic panels work by absorbing sound waves and reducing their reflection in a room.

Passive noise cancelling is effective at reducing low-frequency noise such as background noise. Also includes engine noise and traffic noise. But may not be as effective for high-frequency noise.

Types of passive noise cancelling

Passive noise cancelling refers to the reduction of ambient noise without the use of electronic or digital signal processing. Here are some types of passive noise cancelling:

  1. Over-Ear Headphones: Over-ear headphones have large earcups that fit over your ears, creating a seal that blocks out external noise.
  2. In-Ear Headphones: In-ear headphones, also known as earbuds, create a seal in your ear canal that blocks out external noise.
  3. Noise-Isolating Earbuds: Noise-isolating earbuds are designed to fit snugly in your ear canal and block out external noise.
  4. Earplugs: Earplugs are small foam or silicone inserts that fit into your ear canal, blocking out external noise.
  5. Closed-Back Headphones: Closed-back headphones have a solid outer shell that blocks out external noise and prevents sound from leaking out.
  6. Noise-Blocking Earmuffs: Noise-blocking earmuffs are designed to fit over your ears, creating a seal that blocks out external noise.

These are some of the most common types of passive noise cancelling, each with its unique advantages and disadvantages.

How Do Noise-Cancelling Headphones Work?

This article directly or indirectly evolves mainly around the noise cancelling headphones or audio devices, it’s good idea to look at how the technology works noise cancelling headphones.

How headphones block out sound

Headphones block out sound through a combination of physical and acoustic techniques. Over-ear and on-ear headphones use ear cups that completely surround the ears.

But, in-ear headphones create a seal in the ear canal. This physical barrier between the ears and the external environment reduces the amount of ambient noise.

This ambient noise actually reaches the ears otherwise.

Many headphones also use acoustic techniques such as noise isolation and noise cancellation. Noise isolation involves creating a seal around the ear or in the ear canal. So, this prevents sound from leaking in.

Noise cancellation uses microphones to pick up external noise. This then generates an opposite sound wave to cancel out the incoming noise.

These headphones combine physical and acoustic techniques.

So, these are able to effectively block out external noise. Thus, they provide a more immersive and enjoyable listening experience.

Explanation of over-ear and on-ear headphones

Over-ear and on-ear headphones are two common types of headphones that differ in the way they fit over the ears.

Over-ear headphones are also known as circumaural headphones. They have large ear cups that completely enclose the ears.

They provide excellent sound isolation and are great for blocking out external noise.

Over-ear headphones also tend to be more comfortable for extended listening sessions. This is so because they distribute the weight of the headphones over a larger surface area.

On-ear headphones are also known as supra-aural headphones. They have smaller ear cups that rest on the ears rather than completely enclosing them.

They are typically more compact and portable than over-ear headphones. But, may not provide as much sound isolation.

On-ear headphones can be a good option for those who want a more lightweight and portable headphones. Yet, they don’t want to sacrifice too much sound quality.

How in-ear headphones work

In-ear headphones are also known as earbuds. They work by creating a seal in the ear canal, which helps to block out external noise.

The earbuds are inserted directly into the ear canal, where they rest snugly and securely. This creates a barrier between the ear and the external environment.

Thus, it allows you to listen to your music without the need to turn up the volume to unsafe levels.

Many modern in-ear headphones come with a range of ear tips of different sizes to ensure a comfortable and secure fit. This is important for both sound quality and noise isolation.

Advantages and Disadvantages of Passive Noise Cancelling

Here are the major advantages and disadvantages of noise cancelling technology

Benefits of passive noise cancelling

Passive noise cancelling has several benefits over active noise cancelling. First, it doesn’t require batteries or electronics. So, it makes it a simpler and more reliable solution.

Second, it can be more effective at blocking out low-frequency noise, such as engine rumble or traffic noise.

Third, it can be more comfortable and less fatiguing to wear for extended periods of time. This is because it doesn’t rely on active noise cancellation technology that can create a sense of pressure in the ears.

Finally, passive noise cancelling can be less expensive than active noise cancelling. Therefore, it’s a more accessible option for those on a budget.

Limitations Of Passive Noise Cancelling

While passive noise cancelling has several benefits, it also has some limitations. One of the main limitations is that it is less effective at blocking out high-frequency noise. For example, conversations or high-pitched sounds.

Further, passive noise cancelling techniques can be dependent on the fit and quality of the headphones.

Also, it may depend on the earplugs being used, which can vary from person to person. There is also a limit to how much noise passive noise cancelling can block out.

So, it may not be effective in extremely loud environments.

Finally, passive noise cancelling can be less effective at reducing noise pollution. These sources may sources such as airplanes or construction sites.

This, indeed, require more advanced noise cancelling technologies.

Best Practices for Using Passive Noise Cancelling

Here are a few best practices you can follow along using passive noise cancelling

How To Properly Wear Noise-Cancelling Headphones

To properly wear noise-cancelling headphones, first ensure that the ear cups fully cover your ears, creating a seal that blocks out external noise.

Next, turn on the noise-cancelling feature and adjust the level according to your preferences. It’s important to note that noise-cancelling headphones are designed to reduce constant.

This is also useful to reduce low-frequency noise such as airplane engines or traffic, rather than sudden or high-pitched noises.

Also, make sure to take regular breaks to avoid ear fatigue and maintain good hearing health.

With these tips, you can enjoy a peaceful and immersive listening experience with your noise-cancelling headphones.

How To Adjust Headphones For The Best Sound Quality

To adjust headphones for the best sound quality, start by positioning the ear cups over your ears in a comfortable and secure manner.

Adjust the headband for a snug but not tight fit.

Next, use the audio equalizer settings on your device or audio player to fine-tune the frequency levels to your liking.

If your headphones have a bass boost or other sound-enhancing feature, experiment with these settings to find the right balance for your preferences.

Finally, ensure that your audio source is of high quality and that you are listening at a safe volume level to avoid hearing damage.

How To Maintain Noise-Cancelling Headphones

To maintain noise-cancelling headphones, start by keeping them clean and free of dust and debris. Use a soft cloth to wipe down the ear cups and headband regularly.

Avoid using harsh chemicals or solvents that could damage the materials. Also, store your headphones in a cool, dry place when not in use, and avoid exposing them to extreme temperatures or moisture.

Be careful when folding or storing them to avoid putting pressure on the hinges or ear cups.

Finally, follow the manufacturer’s instructions for charging the battery and avoid overcharging, which can damage the battery and reduce its lifespan.

Common Myths About Passive Noise Cancelling

What are the common myths about passive noise cancelling? Let’s find out.

Misconceptions About Passive Noise Cancelling

Passive noise cancelling is the reduction of external noise by physical barriers, such as the ear cups of headphones, without the use of electronics.

One common misconception is that all headphones with closed-back designs offer significant passive noise cancelling, but this is not always the case.

Another misconception is that passive noise cancelling is as effective as active noise cancelling, which uses electronics to generate sound waves that cancel out external noise.

While passive noise cancelling can help reduce some external noise, it is generally less effective than active noise cancelling and may not be suitable for environments with high levels of noise.

Debunking myths about noise cancelling headphones

There are several myths surrounding noise cancelling headphones. One common myth is that they completely eliminate all external noise.

But in reality, they only cancel out certain types of constant low-frequency noise, such as the hum of an airplane engine or the drone of traffic.

Another myth is that noise cancelling headphones cause hearing damage, but if used responsibly at safe volume levels, they should not cause any harm.

Finally, there is a misconception that noise cancelling headphones are only for travel or noisy environments, but they can also be used for improved focus and concentration in quieter settings.


Passive noise cancelling is a type of noise reduction that works by using physical barriers and materials to block or absorb sound waves.

This can include materials such as foam, silicone, or wax earplugs, as well as soundproofing materials like acoustic panels or insulation.

When inserted into the ear or applied to a surface, these materials create a barrier that reduces the amount of sound that reaches the listener.

While passive noise cancelling can be effective in many environments, it may not be as effective in situations with unpredictable or low-frequency noise, or in poorly insulated environments.

FAQs About Passive Noise Cancelling

Here are some frequently asked questions about Passive Noise Cancelling along with their answers:


Hi, this is Mahendra Shah (also M S in short) a true tech enthusiast with a passion for writing. I have a formal education in computer science and possess a solid foundation in the world of technology. My insatiable hunger for knowledge and my relentless pursuit of self-improvement is a power that drive me throughout the day. As a self-taught and self-learned writer, I have honed my skills over the past decade, specializing in the captivating realm of tech gears, particularly audio devices.