Audiology is about more than hearing loss
Posted on 9 Jul 2021
“My maternal grandmother was born without hearing in her left ear. She was one of my first patients for a hearing aid when her right ear began to decline with age. Then, before I gained my postgraduate qualifications, my paternal grandmother experienced an unfortunate fall – breaking her hip after slipping on a carpet, and consequently suffering further serious health complications. She had been experiencing problems with her balance. I wish I knew then, what I know now- that with some work to strengthen her vestibular (balance) system, the fall may well have been prevented.”
Dr Natalie Buttress, an audiologist at Mediclinic Durbanville, believes that for a long time the word ‘audiologist’ has been synonymous with hearing loss and fitting hearing aids. But she explains that the audiologist is a key weapon in fighting many other sensory challenges that impact our community.
“Audiologists qualify with a minimum 4-year (honours) allied medical degree. Some have specialised or extended their work into post graduate masters and doctoral qualifications, with up to a decade of academic work behind what they do,” explains Natalie.
Her passion for her work is clear and she goes on to describe the potential scope of audiologists’ expertise. “It spans an understanding of the normal hearing process, disorders of the hearing and balance system that affect the function of the auditory (hearing) and vestibular (balance) system, and rehabilitation of those systems.”
How we experience our environment is driven by our six sensory functions. The audiologist’s role is significant if you consider that their work encompasses assisting people of all ages who experience challenges with hearing and balance – developing and supporting two of these six senses – allowing us to better receive and process information from the world around us.
Hearing loss and sound processing
Early diagnosis of hearing loss is important – reducing the impact on the remaining senses, which usually have to adjust to compensate for loss or reduction of other sensory inputs. Natalie recommends that children are tested at birth, and annually to age five. This should be done to mitigate the potential effects of hearing loss on language learning, reading and education. Older children should be assessed every 3 years until adulthood.
Risk is lowest between 20 and 40, although lifestyle issues such as personal music and podcast systems play a role in this group. This means that recommendations for evaluation drop to once per decade. People should be tested again by 50, as hearing loss can have a slow onset and change can be unnoticeable until the loss is already significant. From 50, tests should be every 2-3 years, until 60, when hearing loss becomes more common due to the natural aging process.
Once a hearing loss is identified, annual tests lead to optimum management. One of the field’s most critical new discoveries is the link between hearing loss and cognitive decline, because, while hearing loss may be caused at the level of the ear, it has many knock-on effects for the central auditory nervous system; social and emotional connection or isolation; information-gathering and skill maintenance. Dr Buttress explains that neuroplasticity (the ability of nerves to adapt and for the system to learn) and central nervous system stability are best supported by early intervention and reconnection! Audiologists also play an important role in identifying problems with sound processing after the ear and provide support and rehabilitation for central auditory skills.
Likewise, audiologists have sophisticated equipment to evaluate dizziness to identify the nature of a balance problem and define how it can best be treated. Some balance disorders are rehabilitated by the audiologist, while some require medical management or physiotherapy. Good management can reduce dizziness and restore function and independence.
More than understanding the anatomical and physiological aspects of the auditory and vestibular systems, audiologists are patient-centred therapists who understand subjective perception. Once sensory inputs reach the brain, understanding and interpretation are influenced by everything that an individual has learned, memorised, associated, experienced, or felt previously. The sensory patterns are matched against the brain’s model of the world.
While audiology is an allied medical science that is underpinned by diagnosis and directed towards precise corrections for deficits in the hearing and balance pathways, practicing audiology, says Buttress, is a therapeutic skillset.
“To compassionately listen to each unique individual’s subjective experience of sensory input, and to understand and interpret how we can more accurately normalise our patients’ returning recognition, or to assist them to accept the limitations of their condition, becomes an art,” she explains.
“Audiologists are auditory and balance rehabilitation specialists, with counselling and therapeutic skills, to assist the journey of the patient from the point of loss to restoration of function (to the best degree possible). We accompany the patient while the previously deprived brain acclimatises to restored sensation. For example, when a new hearing device provides sound to a damaged ear, the brain starts to re-categorise sounds. This may require adjustments to the device settings, or at least, supportive encouragement to stick with the process while the brain again learns what footsteps sound like! Or, during balance rehabilitation, while the organs in the ears re-calibrate with the movement of the head and eyes, the audiologist provides carefully graded changes in balance exercises, to harness the brain’s ability to relearn how to use the signals optimally. We are there for our patients, through a carefully guided process, where art and science meet, for an improved quality of life when a sensory system is damaged and function is re-learned,” Natalie passionately explains.
Diagnosis and rehabilitation is possible in both paediatric and adult patients, through behavioural evaluations (using tools such as hearing and understanding acoustic tests; aided functional gain and speech understanding; bedside vestibular tests; quality of life and handicap scales; interviews) as well as objective measures, for example- otoacoustic emissions, which cleverly and painlessly measure an echo from the human cochlea; or vHIT, a precise evaluation of the movement of the eyes compared with the equal but opposite movement of the head, which is governed by our balance system. There are many more of these precise measures. Post-rehabilitative evaluations can provide meaningful data on progress, so that management of the condition may be optimised.
Audiologists as part of a multi-disciplinary team
In understanding their role, you will find audiologists at the heart of many diagnostic and treatment solutions.
• central auditory processing disorders – where the ear may be normal but the brain finds it hard to process information, especially in noisy or difficult conditions
• aural rehabilitation and training- to make sure that the brain understands what it is hearing
• auditory neuropathies – to make decisions on optimal treatment when the auditory nerve does not function normally
• abnormal auditory sensations such as tinnitus (ringing in the ears), misophonia (specific sound anxiety and anger, such as when someone chews or swallows next to you, and hyperacusis (sensitivity to most sound, often also connected to fear and stress)
• auditory (and one day soon, vestibular) implants- electronic implantable devices that bypass certain damaged areas of the audio-vestibular system.
• vestibular system (both otologic or ear-caused and non-otologic-brain or body-caused diagnosis and rehabilitation of reflexes that orientate us: The vestibulo-ocular (balance, head movement and eyes- such as when you are walking and looking side to side); vestibulo-colic (balance organs and neck muscles, to keep your head in the upright plane), and vestibulo-spinal reflexes (balance system with sensation from touch- such as when you are falling backwards but can take a back-step to correct the fall).
• ototoxicity (hearing damage from chemical substances) and vestibulo-toxicity (balance damage from chemical substances).
In some countries, audiologists also provide intraoperative monitoring – measuring nerve responses while doctors operate on the brain.
Many of the congenital and acquired conditions that cause hearing and balance deficits or symptoms, require a multi-disciplinary approach, including audiologists, physiotherapists; occupational therapists; optometrists and ophthalmologists; remedial therapists; speech and language therapists; otorhinolaryngologists; neurologists; oncologists; endocrinologists; haematologists; vascular surgeons; gerontologists; general practitioners; physicians; anaesthetists, and many other disciplines. This is because hearing and balance problems can be secondary to another issue.
The Future of Audiologists and Audiology
It is clear that audiologists should no longer only be synonymous with testing hearing and fitment of hearing aids.
“We are allied medical specialists with a broad scope of practice, serving many patients and contributing to the diagnosis and care of people, together with a wide range of other medical disciplines. As you can hear, I am exceptionally passionate about our future, and hopeful that other disciplines will embrace ALL of our services and skills. The backbone of audiology is holistic patient-centred care, helping people to live their best lives despite hearing or balance challenges,” Natalie concludes.