The world is in the process of reopening, and for many of us that means an end to the remote work trend. Wrenched out of our (likely) peaceful homes, we will be back on the streets among throngs of people who are also returning to noisy commutes. Craving some semblance of our personal bubble, we may reach for a pair of handy earbuds—perhaps the Apple AirPods, by far the global favorite in wireless earbuds.
Despite their popularity, AirPods aren’t amazing at what they do. While their performance may be decent in quiet environments, the listening experience deteriorates in the presence of background noise. This is largely due to the AirPods’ open design and imperfect in-ear fit, which allows ambient sound to leak in and offers very little noise isolation.
Our natural response for drowning out background chatter is to turn up the volume. A comprehensive study has revealed that adults wearing earbuds are far more likely to increase the volume to harmful levels when using earbuds than when wearing over-the-ear headphones. According to Brian Fligor, an audiologist who has conducted extensive research on hearing loss, people typically listen to their music at a level of 13 decibels (dB) above background noise when they’re wearing earbuds.
Doesn’t sound like much? The decibel scale is logarithmic, meaning that noise levels of 70dB are ten times louder than sounds measuring 60dB (normal speaking volume, by the way).
Therefore, listening to music can be especially damaging when you’re in a noisy environment for sustained periods of time. The mean noise level on New York City subway platforms, for example, is 94dB—with 20 percent of the subway system’s spaces exceeding the 100dB mark. Some quick calculations indicate that many commuters are compensating for the loud background noise by listening to their music at 107-113dB levels, risking permanent hearing loss. After all, the Occupational Safety and Health Administration (OSHA) states that workers should be exposed to 85dB noise for no more than eight hours. The World Health Organization (WHO) emphasizes that people should not subject their ears to over 100dB of noise for more than 15 minutes a day.
In 2014, Fligor and his team decided to study people’s headphone-listening levels in urban environments. The research involved asking passersby to place their headphones on a mannequin’s ears, which would record the volume levels of the music that they had been listening to. The results of the study showed that 58 percent of the test population were exceeding their weekly sound exposure limit—and an overwhelming 92 percent of them were wearing earbuds.
It comes as no surprise, then, that hearing loss is becoming prevalent. WHO estimates that 1.1 billion people between the ages of 12 and 35 are at risk of hearing loss, primarily from noise exposure related to recreational activities such as widespread earbud use. In fact, WHO statistics show that 466 million people worldwide currently have debilitating hearing loss (a significant leap from 360 million in 2010), and the figure is expected to nearly double to 900 million by 2050.
In the United States, hearing problems are now the third most common physical ailment behind heart disease and arthritis. According to the National Institute on Deafness and Other Communication Disorders (NIDCD), approximately 37.5 million American adults report hearing trouble, of which 28.8 million could benefit from the use of hearing aids. Tinnitus—characterized by an incessant buzzing in the ears—is afflicting 45 million Americans, while hyperacusis is magnifying everyday sounds to cause intense pain.
“I’m seeing a lot of younger people in their twenties who are coming in with ringing in their ears,” verifies Sarah Mowry, an assistant professor of otolaryngology at Case Western Reserve University School of Medicine. “I think it’s probably related to this all-day earbud use. It’s noise trauma.”
If you regularly find yourself in bustling surroundings, it might be wise to invest in a pair of noise-cancelling headphones. And while Apple’s standard AirPods may have contributed to the worldwide hearing loss problem, the AirPods Pro model is attempting to remedy the situation with its active noise cancellation (ANC) feature. (This is reminiscent of when the Ambrose Diaphonic Ear Lens (ADEL) was invented for the purpose of reducing hearing loss from in-ear monitors.)
Before We Delve into the AirPods Pro—How Does Active Noise Cancellation Work?
The technology—originally created for the comfort of airline pilots on long flights—employs several components to achieve its noise-cancelling effect.
First, tiny microphones along the ear cup detect low-frequency external sounds.
Electronics within the headphones generate a “fingerprint” of the incoming sound wave. The internal circuitry creates an anti-sound wave of the same frequency and amplitude that is phase-inverted by 180 degrees to the original sound wave. This anti-sound wave is fed into the headset’s speaker system along with the normal audio, erasing the original ambient sound wave through destructive interference.
Finally, the term “active” stems from the fact that a rechargeable battery within the headphones provides the energy for noise-cancelling electronic processing to take place.
In addition to ANC technology, noise-cancelling headphones employ the use of sound-absorbing materials to block out ambient noise; this is known as passive noise cancellation. For over-the-ear headphones, these materials are presented in the form of high-density foam ear pads for muffling sound—while for ear buds, gummy tips are utilized for creating a seal inside your ear canal.
According to Brian Brorsbøl, director of product management at Sennheiser Communications, ANC headphones turn down background noise by an average of 30dB, with volume reductions ranging between 20dB and 45dB. You don’t even have to be listening to music—you could simply use the headphones to cancel out background noise, and enjoy some much-needed peace and quiet.
It is important to manage expectations and recognize that—while ANC headphones can reduce low-frequency (below 1kHz) consistent noise such as the low hum of a jet engine—they are less effective in dealing with random high-frequency sounds such as people’s voices. So, if you were hoping to block out the screams of the unhappy baby that’s seated three rows ahead of you on a plane, your ANC headphones will unfortunately not be of much help.
Some users have also reported intense discomfort in their ears due to a phenomenon called “eardrum suck”, which can cause listeners to experience headaches, dizziness or nausea. Tech companies argue that the effect may be psychosomatic, as there has proven to be no air-pressure difference in ANC headphones when measurements were conducted. Could some people’s brains be interpreting the drastic change in sound levels as a decompression, even if the eardrums themselves are physically unaffected? Or is it possible that our instruments aren’t equipped to detect such infinitesimal pressure changes yet? According to this TED talk on the science of hearing, our body can detect air pressure changes by the “billionths of the atmospheric level.”
The AirPods Pro as ANC headphones—with Basic Hearing Aid Functionality
Apple’s AirPods Pro model comes with a range of attractive features that improve on its predecessor’s flaws.
For one, AirPods Pro earbuds now have custom ear tips to provide enhanced fit and create a tight seal around the ear for both passive and active noise cancellation to work effectively.
Apple goes one step further by allowing you to conduct a quick audio test to ensure that your earbuds are fitted correctly in your ears.
A tiny pressure valve inside the AirPods Pro releases any pressure that may build up in your ear due to the earbuds’ advanced noise-isolating design. Sound quality in these earphones is reported to be excellent in noisy environments, with better bass than is provided by the standard AirPods because of the active noise cancellation. A sound recognition setting notifies users about noises detected by their Apple device, ranging from sirens and smoke alarms to the chime of doorbells.
The AirPods Pro allows you to toggle between customizable levels of noise cancellation and a new feature called Transparency mode, which switches you to complete awareness of your surroundings without having to remove your headphones—much like typical hearing aids do.
An accessibility feature called Live Listen allows your AirPods Pro to amplify sound, turning the earbuds into basic hearing aids. Instead of asking someone to speak up if you’re hard of hearing, you can turn on Live Listen mode and hand your iPhone to the person for them to talk into. Your iPhone acts as a remote microphone and sends the audio into your AirPods Pro, amplifying what is being said while cutting out background noise. (Remember to turn off Live Listen mode when you’re done using it, though, or else your music will sound extremely distorted.)
Apple’s iOS 14 update further aims to turn the AirPods Pro into a hearing aid through its Headphone Accommodations feature—which enables all amplification to take place directly through the earbuds, removing the need for sounds to go through an iPhone’s microphone. This can be a cost-effective alternative to proper hearing aids if you have minor hearing issues. For comparison, the AirPods Pro costs $249, while the average price of a single hearing aid is $2,372—with premium models setting you back anywhere from $4,000 to $6,000.
“For the past 5 years I have predicted that major consumer companies like Bose, Sony, Sennheiser, and Apple would make entries into the world of ‘over-the-counter’ hearing aids,” asserts Dr. Brad Stewart, an audiologist who owns Clear Life Hearing in Allen, Texas. “Consumers of hearing aids have long expressed frustration about the high cost and hands-on care associated with the treatment of hearing loss. My industry certainly appears, at least from the outside, to be one that’s ripe for disruption.”
Indeed, Apple is not the only company with its foot in the hearing aid market. Australian company Nuheara has similarly released a pair of wireless earbuds with a hearing boost function, while Bose is marketing its set of conversation-enhancing headphones, which it calls “hearphones.”
What Are Some Important Considerations When Using the AirPods Pro as a Hearing Aid?
It is necessary to acknowledge the potential limitations of the AirPods Pro when it comes to their function as hearing aids.
For starters, there is the possibility of audio lag when sound is processed on a phone and transmitted to the AirPods Pro for playback.
“The challenge of using smartphone processing is that auditory information must be presented within 80 milliseconds,” says Dr. Chad Ruffin, an otolaryngology expert. “If processing and relaying this information cannot occur during this time, it will make communication harder. This is because the lipreading cues can become out of sync with the amplified audio.”
Battery life is another crucial factor. According to Dr. Cliff Olson, founder of Applied Hearing Solutions in Phoenix, Arizona, the AirPods Pro are expected to suffer from a very short battery life when used as hearing aids—with users likely getting no more than a couple hours’ worth of battery life at a time.
In his YouTube video discussing the capabilities of the AirPods Pro as hearing aids, Dr. Olson offers further insights.
“I suspect that Apple will do a couple of things really well, but I also expect them to miss the boat on a variety of different important factors. There are still a lot of questions that we do not know the answers to. How much customization will we be able to do with the AirPods Pro from an amplification perspective? Will the amplification actually meet real ear measurement prescriptive targets? And the biggest question of them all is, will they be able to function well in a background noise setting? It’s easy to cancel out extraneous sound when you’re just trying to stream audio in from a device. When you’re trying to separate speech from background noise, that becomes significantly more difficult to do—and who knows whether or not the AirPods Pro will be able to do that? Each one of the answers to these questions will ultimately be make-it-or-break-it factors when it comes to using these guys as actual hearing aids.”
In any case, Apple is a major innovation leader with considerable influence in the tech world. The company has the power to lay the groundwork for a hearing device industry disruption, while simultaneously opening many people’s eyes to the need for hearing care treatment.
Some experts predict that there will be more crossover and eventual convergence between headphones and hearing aids—with headphones improving on speech-boosting abilities, and hearing aids incorporating music streaming. If actualized, the idea should be a resounding success.