How We Hear

Although we do it automatically, the hearing process involves a series of complex steps.

  1. Sound waves enter the ear canal and vibrate the eardrum

  2. The eardrum is attached to three tiny bones (the malleus, the incus and the stapes), which move with the eardrum, magnifying the signal made by the sound waves.

  3. The signal is then transferred by the stapes to the cochlea (the hearing organ). The cochlea is a snail- or shell-shaped organ, about the size of a pea, that is filled with fluid.

  4. The vibrations from the stapes causes the formation of fluid waves within the cochlea, which causes movement of specialised sensory cells known as hair cells. The hair cells located on the base of the cochlea move in response to higher-pitched sounds such as birdsong. The hair cells located near the top of the cochlea move in response to lower-pitched sounds such as thunder.

  5. As the hair cells move, electrical signals are sent via the auditory nerves to the brain, where the sound is interpreted as sounds that we understand, such as speech or music.

Why healthy hearing is important

Communication

Communication is essential to building and maintaining our relationships with others. Having healthy hearing allows us to interact effectively with friends, family and colleagues and is an important component to feeling engaged with our surroundings. It is common for people with hearing loss to withdraw from social situations due to frustration, and can lead to social isolation.

Safety

We use our senses to keep ourselves safe. Our ability to hear a fire alarm, detect an approaching emergency vehicle, or perceive a baby’s cry can be affected by hearing loss. Healthy hearing allows us to remain in touch with our environment, and keep yourself and others safe.

Independence

Being able to hear adequately provides us with greater ability to carry out employment duties, and interact with necessary communication partners for important day-to-day tasks such as receiving healthcare and buying groceries.

Health

Hearing loss may be indicative of other health issues, as there have been links established between hearing loss and balance disorders, cardiovascular disease (1,2) and diabetes (3). While cardiovascular disease and diabetes can potentially have a detrimental impact on our hearing, more research is required in this field to determine whether successful management of these would prevent hearing loss (2,3). Treating hearing loss at the earliest stage possible may have a positive effect for healthy aging, however it is important to note that there is no causal link between hearing loss and dementia. Whilst hearing loss has been associated with a greater risk of dementia, hearing loss does not cause cognitive decline, and further research is required in this space.

Quality of life

Hearing is a great source of pleasure and emotion for most people. Examples of healthy hearing which affect quality of life include experiencing an exquisite piece of music, listening to your grandchildren’s laughter, or immersing yourself in the fascinating sounds of nature.

How we can protect our hearing

For many people, hearing loss is inevitable, as age-related hearing loss is likely to be inherited. Hearing loss may also occur or be exacerbated, however, by exposure to excessive sound or noise. Hearing loss caused by noise exposure is often not perceived by the individual at the moment it occurs, and is most likely to instead present later in life. Our hearing can also be detrimentally affected by infection and trauma to the ear(s). Once our hearing is damaged, in many cases, it is irreversible. This is why it is extremely important for us to take measures to protect the hearing we have. Below are some of the ways in which we can protect our hearing and our ears.

Reducing your exposure to loud sounds

The degree of hearing damage caused is dependant on the volume of the sound, as well as the duration of the exposure to the sound. Safe Work Australia (4) recommends that a maximum volume of 85 decibels (dBA) is safe for a maximum of 8 hours. Therefore, reducing the time spent in the presence of loud sounds such as power tools, or loud music at a concert is the best way to protect your hearing in the long term. Sounds of 85 decibels or louder are considered dangerous over time. Regardless of what is causing the sound, if you need to shout at the person next to you for them to hear you, you can presume it is causing damage to your ears. For situations where loud noises are unavoidable, use hearing protection such as custom fitted plugs or earmuffs. It is also important to take regular breaks in quiet settings, to allow your ears to recover. If you are a musician, we can help you with custom earplugs, which have filters that allow for a more natural sound by letting more frequencies through, but reduce the overall volume to make the sound intensity less harmful.

Turn down your headphones

If you are listening to music through headphones, try to limit the amount of time you are listening at a high volume. A good rule of thumb is that if someone near you can hear the music from your headphones, it is too loud! Keeping the volume to 60% is safe for 60 minutes, however you should take a break after this time. Noise-cancelling headphones can be a great way of achieving a more intense sound with less volume, as you do not have to turn the headphones to compensate for the background noise. Over-ear headphones may also be safer than earbuds, as the sound source is not as close to your eardrum; as with all sound, the closer the source to the eardrum, the louder it will be to our ears.

Keep your ears dry

If the ear canal is kept moist for extended periods, this can lead to bacterial infections such as “swimmer’s ear”, which can be both painful and a risk to your hearing ability in the long term. Tilt your head to the side if you can feel water in your ear after swimming or bathing, and use a towel or tissue to gently absorb excess moisture. For individuals who spend a lot of time in the water, a drying ear spray can be useful, such as DryEars Swimmer's Ear Prevention Spray.

Avoid putting cotton buds (or other items!) in your ears

Earwax is normal, and is produced by our ears to help clean and protect themselves by trapping dust, repelling water and helping to prevent infection. Earwax should naturally work its way out of the ear, but for some individuals, the amount of earwax produced is slightly more than usual. An overproduction of earwax can prevent it from migrating out of the ear canal as it should. In these cases, earwax removal should be performed by an expert, such as a nurse or audiologist with appropriate training. By using cotton buds (or other items such as a bobby pin), not only are you likely to pus the way in further and compact it, you may risk perforating your eardrum and damaging the delicate structures behind it. This can lead to pain, hearing loss and potentially infection. If you think (or know) you have wax build up, please book in for a wax removal appointment. For more information on earwax and the process of earwax removal, check out our blog post on this subject here.

Regular hearing checks

Hearing loss usually develops gradually, so it is important to have your hearing checked regularly by your audiologist. If hearing loss has been detected, we recommend having your hearing re-checked annually, so that your audiologist can ensure your hearing aids are giving you the optimum access to sound. Your audiologist can also check for wax build up, signs of infection, and other abnormalities.

References:

  1. Baiduc RR, Sun JW, Berry CM, Anderson, M and Vance EA (2023) ‘Relationship of cardiovascular disease risk and hearing loss in a clinical population’, Scientific Reports, doi: 10.1038/s41598-023-28599-9

  2. Tan HE, Lan NSR, Knuiman MW, Divitini ML, Swanepoel DW, Hunter M, Brennan-Jones CG, Hung J, EIkelboom RH and Santa Maria PL (2017) ‘Associations between cardiovascular disease and its risk factors with hearing loss-A cross-sectional analysis’, Clinical Otolaryngology, 43(1):172-181, doi: 10.1111/coa.12936

  3. Wattamwar K, Qian ZJ, Otter J, Leskowitz MJ, Caruana FF, Siedlecki B, Spitzer JB and  Lalwani AK (2018) ‘Association of Cardiovascular Comorbidities With Hearing Loss in the Older Old’, JAMA Otolaryngology Head and Neck Surgery, 144(7):623-629, doi:10.1001/jamaoto.2018.0643

  4. Safe Work Australia 2023, Noise, Safe Work Australia, viewed 25 November 2023, <https://www.safeworkaustralia.gov.au/safety-topic/hazards/noise/overview#:~:text=The%20noise%20exposure%20standard&text=Workers%20must%20not%20be%20exposed,on%20decibels%20and%20time%20exposed>