Children, Headphones & Noise-Induced Hearing Loss

Children, Headphones & Noise-Induced Hearing Loss

Children in San Diego and throughout the country are at an ever growing risk of developing hearing loss. The number of Americans with hearing loss has actually doubled within the past 30 years. This steep increase can be partially attributed to the use of personal music players.

children headphones and noise-induced hearing loss

San Diego audiologists explain that the danger of a personal music player is noise-induced hearing loss. Every sound is measured in decibels (dB). Listening to anything over 85 dB (heavy city traffic) can cause damage after eight hours. Listening to anything over 100 dB (motorcycle) can cause damage within 15 minutes. Listening to anything over 120 dB (jackhammer) can cause damage immediately.


Audiologists have been conducting research on personal music players. One study found that 25 percent of those who use a personal music player are exposed to daily noise that is high enough to cause damage. A 2010 study found that a standard set of earbuds connected to an iPod set to its maximum volume produced an average sound level of 96 dB. This is higher than what is legally allowed in most workplaces. Another study found that 90 percent of all adolescents listen to music using earbuds; almost half listened at a high-volume setting.


The simplest way to correct this problem would be to turn the music down. But if you are a parent you know how much children enjoy following rules. Your San Diego audiologist recommends implementing the 60/60 rule. This rule states that you can listen to your music at 60 percent of its maximum volume for 60 minutes a day.  Researchers have determined that this volume for this length of time will not cause any harm to your hearing.


Below are some things to try if your child still listens to their music too loudly.

  • Replace your child’s in-ear bud-style headphones with an over-the-ear model.
  • Set a sound limit. Most music players have a parental option. With this you can set a password-protected listening limit.
  • Purchase kid-safe headphones. Headphones designed specifically for children often have a lower-than-normal maximum volume level.


If you need any additional help figuring out how to protect your child from noise-induced hearing loss, contact your local San Diego audiologist.

The Hidden Hearing Loss Effect

Each day we all experience sound in the environment.  Many of these sounds are low intensity, satisfying, and others are the mundane sounds of life, such as television, radio, household appliances, cars running, traffic, etc.  Most of these sounds are at very safe levels and do not cause any danger to hearing.

ear-foliclesWe also know however, that there are loud sounds, some brief, other long lasting, that can injure hearing causing Noise Induced Hearing Loss (NIHL). We know that NIHL can be immediate or be incurred over a long period.  It can be temporary, or permanent affecting only one or both ears.  We also know that this type of hearing loss, though one of the most prevalent, can be prevented by less exposure to loud noise, music or other sounds.

According to the NICD (2016), about 15% of the US population between the ages of 20 and 69 or 26 million people have hearing loss that was probably caused by noise exposure at work or in those noisy, but fun leisure activities.  Until recently, the thought was that most NIHL was caused by significant damage or death of the hair cells within the cochlea.  Rabinowitz (2000) summarized the typical thoughts on the pathophysiology of NIHL.   He felt that, “Sounds must exert a shearing force on the stereo cilia of the hair cells lining the basilar membrane of the cochlea. When excessive, this force can lead to cellular metabolic overload, cell damage and cell death. Noise-induced hearing loss therefore represents excessive “wear and tear” on the delicate inner ear structures. Once exposure to damaging noise levels is discontinued, further significant progression of hearing loss stops. Individual susceptibility to noise-induced hearing loss varies greatly, but the reason that some persons are more resistant to it while others are more susceptible is not well understood.”   For decades’ studies from around the world have concurred with this suggestion that NIHL and age related hearing loss have focused upon the loss of these stereo cilia, often called hair cells.  While these stereo cilia are vulnerable, researchers at the Massachusetts Eye and Ear Infirmary’s  (MEEI) Eaton Peabody Laboratory at Harvard Medical School have now shown that nerve fibers are even more vulnerable to damage from noise.

ear_cell_comparison1In the normal ear, sound waves are transmitted through the middle ear bones to the inner ear, where they cause vibrations in the sensory epithelium called the “organ of Corti.” The organ of Corti turns this mechanical function into electrical pulse trains in the fibers of the cochlear nerve, which then carries the information to the brain for analysis of the acoustic scene.  Dr. Charles Liberman, Director of MEEIs Eaton Peabody Laboratory, is an expert on the peripheral auditory system.  He explains that, “The organ of Corti contains two types of sensory cells: outer and inner hair cells,” explained Charles Liberman, director of MEEI’s Eaton Peabody Laboratory.

“The sensory cells are called ‘hair cells’ because of the hair-like tufts of microvilla on their apical surfaces, which are called ‘stereo cilia.’ Bending the stereo cilia opens ion channels in the nerve hair cells and allows a current to flow that ultimately excites the fibers of the cochlear nerve. This is the heart of the mechanical-to-electrical transduction process in the inner ear.”

How did this hidden hearing loss remain “hidden” so long?   Liberman felt that there are two main reasons for this, ”First, the field of auditory neuroscience didn’t appreciate until recently that you can lose up to 90 percent of your cochlear nerve fibers without a change in the ability to detect a tone in quiet,” he said. “Tone detection in quiet is the basis of the threshold audiogram — the gold standard test of hearing function. The fact that thresholds may transiently elevate and then recover within hours or days after an acoustic overexposure doesn’t mean that the inner ear has recovered.” “And Second, the most vulnerable part of the neuron turns out to be the synapse between the nerve terminal and the hair cell, and it happens to be difficult to see. “Until recently, they could only be seen and counted by using an electron microscope,”

In their research, Liberman and Sharon Kujawa, Director of Audiology for MEEI stained synapses with antibodies that target molecular structures within the synapse, which allowed the synapses to be seen and easily counted in a light microscope. This enabled them to view many synapses on hair cells in a normal ear, as well as the greatly reduced numbers of synapses hair cells following a noise exposure that caused only a transient elevation of thresholds.

hearing-loss-ct-scanThey noted that “each missing synapse represents a missing cochlear nerve that has been disconnected due to retraction of the terminal segment — it will never reconnect.”  Liberman also indicated that, “It no longer responds to sound and, within a few months is almost certainly unwarranted,” The researchers are aware of the public health implications of their findings in that all our federal noise exposure guidelines assume that noise exposures cause only transient threshold elevation are benign and now that assumption is certainly outdated.

While their research was conducted on mammalian ears, mouse, guinea pig and chinchillas, there is every reason to believe that that this same phenomenon exists in humans.  The study has led to the possibility that maybe these synapse issues can be reversible, continuing research goes on in their laboratory on this issue.

Mapping Hearing Loss Solutions

mapping our hearing loss, the charitable arm of the world’s largest search engine, is supporting  World Wide Hearing (WWH) to find a solution to what the World Health Organization (WHO) has described as one of the largest disabilities on the planet.

Hearing loss.

It affects one-third of people over the age of 65 and more than 1 billion young people are at risk for impaired hearing.

The WHO highlighted the risk of hearing loss in a release in early 2015 stating that half of young people, between the ages of 12-35 “are exposed to unsafe levels of sound.”
Through Google Impact Challenge: Disabilities, World Wide Hearing in Montreal, was awarded a grant to do something never done before. Develop and map out data points on hearing health from across the world in the hopes of better understanding hearing loss.


10,000 people will have their hearing tested as researchers try to better understand the dynamics of hearing loss.


This global database will be the first step in understanding and addressing the dynamics of this potentially debilitating disability.

WWH Executive Director Audra Renyi grew up experiencing the first hand impacts of hearing loss.  Her father suffered hearing loss as a child when he contracted an ear infection in his native Romania.

“So many people live with this disability that often goes under the radar,”

says Renyi.

Compounding the fact is that new research has shown a direct link between hearing health and mental health. How well you hear is directly linked to your risk for dementia, depression and anxiety.

Researchers have found that cognitive decline increases by up to 40% as hearing slides. With young people, hearing loss can have serious impacts on development.

hearing loss mapping

Children and young people who suffer from hearing loss are at a greater risk for depression and anxiety; they also face challenges in school, lower self-esteem and social isolation. How well you hear is connected to how you feel and for young people, how well they develop; making early diagnosis and treatment vital.

The first step for the team is to test thousands of ears all over the world and map out the world’s hearing health.

To make this possible, WWH needed a technology partner who could help make this a reality. They partnered with Clearwater Clinical, a Canadian company and creators of the first clinically validated iPad audiometer. “No other hearing testing equipment is as compact, easy-to-use, and fun,” says Dr. Matthew Bromwich, Otolaryngologist and Co-founder of the company

It’s called SHOEBOX Audiometry and it’s comprised of software that is loaded onto an iPad and shipped with calibrated headphones. The solution is an audiometer that can administer diagnostic hearing tests.   The test is designed to feel more like a computer game, and the data it produces is transmitted and stored safely and securely onto the cloud.

Mobile medicine, like the kind delivered through SHOEBOX is an important step in being able to reach communities. The simplicity of the technology allows for quick and easy deployment to parts of the world where people may have never had their hearing tested.


But not all apps are created equal. A quick Google search will pull up lots of tablet and phone applications on hearing testing, many of which can provide good, general screening results. However, only a handful of apps like SHOEBOX, Frye Colt, Piccolo and iAudiometer provide a full medical diagnostic and essentially remotely replicate a traditional audiology booth.


For Renyi the new approach made sense.
“We wanted to find mobile solutions and solutions that we had confidence in. There is solid research behind it and we have a lot of confidence in the data,”says Renyi.

Another important factor is that while the data must be interpreted by an audiologist, the hearing tests can be performed by individuals that aren’t hearing health professionals.

This novel approach is already being well received. In Guatemala, technicians have been trained and have administered tests in several communities.

The simplicity of the technology means that with some hands-on training, individuals – including many women – are being empowered with the opportunity to help perform vital health services, and in turn, support their families.

The global hearing project is performing hearing screenings in the Mohawk community south of Montreal this month with plans for testing in South America and Southeast Asia later this year.

Reprinted with permission from
Please visit for the original article: Mapping Out Solutions to Hearing Loss

Hearing Health and Outdoor Concerts

hearing protection san diego

The summer is winding down, and in other parts of the country, so are outdoor music events. However, San Diego’s incredible climate allows us the distinct pleasure of enjoying outdoor concerts well into the fall. For example, the Birch Aquarium at Scripps provides unparalleled ocean views during its summer-to-fall concert series. Humphrey’s Concerts at the Bay is another art performance series that offers live music and comedy through the end of October. With several weeks left of exceptional outdoor music performances, be sure your ears are prepared for the task.

Your ability to hear properly is a key factor in the overall experience of a musical event. For that reason, many individuals decline using foam earplugs. As professionals in hearing health and technology, we understand that these devices can slightly alter the sound experience by muffling certain frequencies, but did you know there are ways to replicate the sound at less dangerous noise levels?

There is an advanced form of hearing protection that actually processes incoming sound and replicates the frequencies at a lower volume. This high-fidelity technology is commonly used in place of traditional earplugs for musicians and is referred to as “musicians earplugs.” An audiologist performs an impression of the ear to provide a custom-fitted earmold that won’t interfere with the sound experience.

For those with some degree of hearing loss, the best way to experience live performances is by using hearing aids. The technology has improved exponentially in the past several years. In modern devices, digital processors are used to reduce the volume of unwanted sounds and amplify quieter frequencies. New digital devices can also be programmed to treat your specific hearing loss in a variety of settings, including concerts.

Taking charge of your hearing health ensures you are getting the most out of every concert. If you are hearing impaired, we encourage you to speak to an audiologist, who will help you in selecting the best hearing aids. San Diego Hearing Center has been providing hearing evaluations, diagnostics and treatments to our community for years. To learn more about hearing protection and treatment, contact our staff at (619) 298-8546.