For the modern day world where things can be fast paced and stresses high, noise cancelling headphones are often considered a safe haven to block the outside world and enjoy our music. Blocking out outside disruptions can make them a tempting purchase and it is reason why noise cancelling headphones are very popular.
However some users may question whether in fact this form of technology is safe to use. To investigate, we break down how noise cancelling technology works as well as their use cases so you will be in a more informed position when making your own purchase.
What Is Sound?
To really get the concept behind noise cancelling, it’s better to understand what sound is. Sound are vibrations which propagate through a transmission medium such as air. These vibrations cause air to expand (in process called rarefaction) and compress.
These changes are measured and called pressure amplitude. These are consequently interpreted by our ears and brains. The main concept behind the sound is that the louder it becomes, the more extreme the amplitude.
Most music lovers face the issue of sound interference or blockage due to external noises. This situation is very well explained when you try listening to music on a CD or digital audio player on a plane. The roar of the aeroplane engines will often mean having to increase the volume of your headphones to listen to the sound. Even then, the sound you are interpreting may not be the cleanest when surrounded by a noisy ambient environment.
Types of Noise Cancelling Headphones
There are two types of noise cancelling headphones: active and passively isolating. Generally, all headphones can provide a large amount of passive noise reduction. This is due to the materials present in them that block out sound waves of high frequencies. Circumaural headphones are the better choice on the market to extract the best from noise isolation headphones
They are made to maximize filtering properties, which is due to layers of high-density foam and some other sound absorbing material that makes it heavier than the other headphones. The turnoff with these headphones is that they can be heavier than its counterparts, but their design enables noise reduction of up to 5 dB. Passive headphones have a big limitation as jet engines create 75 to 80 dB of noise making them unsuitable in this context.
This is where the use of active noise cancelling headphones comes in.
Active noise cancelling headphones do literally everything the passive headphones can do and more. They are designed to create a barrier that blocks high frequency sound waves. They also erase low frequency sound waves.
How Do Noise Cancelling Headphones Work
Active noise cancelling headphones use microphones to capture ambient sound and onboard electronics generate sound waves that are 180 degrees out of phase with the unwanted noise, in essence ‘cancelling’ them out.
Several components are joined to create this technology.
1. Microphone: In the ear cup, a microphone is placed. So it can ‘listen’ to external sounds that will be blocked actively.
2. Noise-cancelling circuitry: Inside the ear cup, a small technology is placed to sense to get all the ambient noises from the microphone. After this is done, a ‘fingerprint’ of the noise is generated making sure the amplitude of the incoming wave and the frequency is noted. A new wave that is 180 degrees out of phase with the incoming noise wave is then formed.
3. Speaker: Anti-sound is then fed into the headphones along with the normal audio. Anti-sound is produced by the noise cancelling circuitry and it erases noise by destructive interference. Anti-sound doesn’t affect the sound waves in the normal audio.
4. Battery: As the name implies, energy is always added to produce a noise cancelling effect. The battery of this type of headphone is rechargeable.
With these components, active noise cancelling headphones are able to remove the noise of up to 20 dB in wavelength. This implies that 70% of ambient noise is blocked making noises cancelling headphones the best for the airline, open office environments and train travel.
Do Noise Cancelling Headphones Protect Hearing?
Yes, noise cancelling headphones protect the ears. Both the active and passive types.
Passive noise isolating headphones are designed to protect the ears from loud external sounds, especially transient ones like explosions and gunshots. They also offer additional protection to people who work in very loud places but have the need to communicate. Such examples are workers in construction sites that operate heavy machinery and pilots.
Active noise cancelling (ANC) headphones does the same work of protecting the ears by reducing the volume at which you listen to music through the headphones. Loud music affects the cells of the minuscule sensory hairs in the inner ear. These sensory hairs send auditory signals to the brain. Less exposure to loud music leads to less potential damage to those cells.
Be sure to note that ANC headphones won’t protect you from explosive, sudden sounds because they solely have the active noise cancelling technology in them. Unlike their other counterparts that have a protective sealing. To get optimal protection, a pair of headphones that provides the passive noise isolating structure coupled with ANC technology will give you the overall protection needed from noise. Measuring headphone decibels is another way to limit overall listening volumes and protecting hearing.
Active Noise Cancelling vs Passive Noise Isolation
Passive noise headphones block sounds, active noise cancelling aims to eliminate them. Bose QuietComfort 35 II are examples of flagship active noise cancelling headphones that got their name from the in built technology that allows the headphones to seek out and destroy ambient noises before it gets to the ears.
These headphones feature a very small microphone in each ear cup that listens and grabs ambient noise frequencies coming from the outside. It then generates opposite sound frequencies which are out of phase with ambient noise – effectively cancelling out the sounds. The only thing you hear is music and nothing else in theory.
Passive noise isolation is a common term used by audio marketers. These headphones perform their trick by using natural shapes and materials to eliminate ambient sound. Passive noise isolating headphones don’t come with built in technology and microphones that look for ambient sounds to destroy. They don’t have a built-in battery, which explains the name passive. Passive noise isolation can be literally anything that covers your ears that can isolate noise like ear muffs.
High end headphones don’t have the active noise cancellation technology because this form of technology does tend to affect sound quality. To effectively cancel out ambient noise frequencies, most noise cancelling headphones need to have antiphase to add to their counter frequencies.
If you notice, most professional DJs even though most of their time is spent in a noisy environment can favor cans like the HD25 which will aid hearing with active cancellation. The great advantage to most noise cancelling headphones is that you have the option to turn active noise cancelling one or off. An example of headphones with this technology is the Bose Headphones 700. This technology is perfect when you’re listening to music using your headphones in a quiet environment.
Active noise cancelling headphones rely on their microphones a lot. They don’t have much passive noise isolation like the other non anti noise isolation headphones do. Here’s something you can do if you have ANC headphones, try switching the noise cancelling on and off and see how it affects the quality of your sound.
So Which One is Better?
It depends on your needs, but an average person will enjoy the active noise cancelling headphones better. The advantages are that you are able to listen to music on low volumes as ambient noise is significantly reduced.
For professionals whose field of work demands very high quality and unfiltered sound or audiophile enthusiasts wishing the best sound quality, passively noise cancelling headphones may be the better choice.
Safety Issues Concerning Noise Cancelling Headphones
The benefits of using noise cancelling headphone are plentiful. However, there are some safety-related user complaints that have been associated with these type of headphones throughout the years.
Let’s look into some of them.
Pressure on the ears
Some user complaints associated with noise cancelling earphones include jaw pains, migraines, dizziness, and ear pressure. The ear pressure, specifically, is compared to a similar sort of ear pressure one feels on a rising plane. To comprehend this better, it’s crucial to know how barometric pressure changes influence us.
At the point when we take off in a plane, the air pressure inside the ear quickly surpasses the pressure outside of the ear. This consequently causes the tympanic membrane (eardrum) to swell outwards causing us to feel this pressure on the ear.
Active noise cancelling headphones cancel out low frequency sounds and sometimes can be used on the solid ground just to get the effect on being up in the air. Even when you’re using the headphones to play games at home, the brain may think are pressure changes which may lead to a feeling of having pressure in the ears and headaches.
While some users adapt well to ANC headphones and don’t experience any symptoms. Some others can use them and feel no ear pressure for a few hours before they feel the need to take it off. The problem is, this feeling has no cure. Most people who struggle with the symptoms have to sell their active noise cancelling headphones for the other passive noise isolating ones.
Most manufacturers still don’t know about this but some noise cancelling headphones are made for relief, they possess the pressure-relief technology that distributes air pressure all over the ears. This enables it to be effectively used while travelling abroad enabling a safer listening experience and great sound quality.
Tinnitus occurs when a patient is feeling persistent ringing sounds in the ears. It becomes more evident when there is no external background noise in play. Tinnitus affects anyone of any age. This disorder can be caused by damages or interference with the inner ears sensitive structures.
There have been some reports about the users of ANC headphones experiencing tinnitus. However, there is no proof or correlation to link these types of headphones with tinnitus. A theory was proposed that tinnitus which occurs in some ANC headphones users is caused by the high noise reduction of the headphones.
If you frequently study with noise-cancelling headphones in a library or hall you will notice ambient noise is significantly reduced. In this context, all ringing sounds will be felt very consciously and explain why some users may feel this sensation.
Is Noise Cancelling Worth It?
If you want to enjoy listening to music everyday without being disturbed by external noise then noise cancelling headphones are a good choice. Aside from this, there are a variety of other factors you should consider when you want to get noise cancelling headphones. The first thing you should think about is the pros and cons. Take a deep look critically into those devices and check which one is a great fit for you.
Advantages of Using Noise Cancelling Headphones
1. Removes external noise: As stated before they block external sounds ranging from the voice of other people to low frequency sounds like the hum of an engine.
2. They improve the listening experience: Noise cancelling headphones allows you to focus and concentrate. It might get very frustrating when you’re trying to study while a roommate is playing loudly on the iPod. You can suppress external sounds by putting on your headphones.
3. They work perfectly for focus and travel: To make your journey more peaceful and stress-free, you can use your noise cancelling headphones while on the bus. In most cases, for travelling headphones are recommended as long you’re not the one behind the wheel.
4. Overall ear protection: With the ANC technology, music can be listened to on quieter volumes since ambient noises are blocked.
Disadvantages of Using Noise Cancelling Headphones
1. More expensive: Owing to their electronics and technology, noise cancelling headphones tend to cost more than their passively isolating equivalent. However, there are plenty of affordable options on the market.
2. They consume a lot of power: Since these type of headphones use microphones to constantly source the frequencies of the outside, they require energy which consumes battery life.
3. Sound quality may be reduced: Active noise cancelling headphones use antisound frequencies via an amplifier to cancel out ambient noises. In this process, they tend to affect overall sound quality.
4. Reduced awareness of surroundings: Since they are effective at reducing outside sound, this may be a problem when users require some degree of awareness of the outside world.
So all in all, noise cancelling headphones are safe to use. The technology used in noise-cancelling headphones is created specifically to protect the hearing of pilots against the plane engine’s loud sound. This have proven an efficient way of preventing hearing loss and eliminating noise-related stress. They do this by eliminating continuous background noises in low frequency like a rumble of an airplane’s engine or the hum of machines. The wearer experiences clear sound and does not need to raise the headphones volume. In addition, they can be a great option for those with sensitive hearing and children with hearing defects.
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