When it comes to enhancing communication and increasing sound quality, hearing aids are especially helpful for individuals who have otosclerosis, a degenerative ear condition marked by abnormal growth of bone in the ear. Hearing loss results from this condition's disruption of sound transmission. For those with otosclerosis, different types of hearing aids can greatly improve their quality of life and ability to hear. To effectively treat this illness and achieve better results, it is imperative to comprehend the function that hearing aids play in its management.

Overview

Hearing aids are smart devices that are used to assist people who are hard of hearing. This works by amplifying sound, similar to a mini speaker, for the person wearing it. There are different types of hearing aids with different sizes and styles to choose from, allowing personalisation and customisation for each person depending on their condition.¹ Otosclerosis is a condition by which a bone located in the ear has an abnormality like if it hardens or gets stuck, and causes hearing loss.² Three bones make up the middle ear; malleus, stapes, and incus. If one of these bones gets stuck, it halts the vibration which prevents sound from going through. According to the National Institute on Deafness and Other Communication Disorders (NIDCD), white, middle-aged assigned female at birth (AFAB) individuals are most at risk and this condition mostly affects the caucasian demographic in the US.² However, it is important to note a partiality in this statistic could be due to how people of colour both in and outside the US are oftentimes unable to access the same level of healthcare, causing their exclusion from this statistic. 

Understanding otosclerosis

Causes of Otosclerosis

Like most diseases, genetics play a big factor in the development of otosclerosis. Numerous genetic loci can impact the development and or function of the middle ear bones, and oftentimes the mutations of these particular loci can cause otosclerosis. It is considered to be autosomal dominant inheritance. A genome-wide association study (GWAS) on the human genome has found the specific loci that are responsible for the bones of the ear. The meta-analysis of the GWAS conducted by Rämö et al. analysed loci most closely associated with otosclerosis.³ It was concluded that 27 significant loci were chosen to be analysed statistically. After running the statistics test, 4 loci were reported while 23 were considered novel. In another research article written in 2010 by Ealy and Smith, the relevant loci to otosclerosis are explained with details as to which aspect of the human body it affects.⁴ Eight loci mapped and named OTSC1-8 (meaning OTSC1, OTSC2…OTSC8) each found in different chromosomes, are found relevant to otosclerosis, for example, collagen synthesis. Other loci named COL1A1, TGFβ superfamily, CD46 and more are also sporadically associated. For more details and explanations on these specific gene loci, follow the link to the Ealy and Smith research article. It is also important to note that the expression of genes is also largely influenced by the environment. The mutations of these loci could be due to environmental factors or inheritance, hence causing its expression. 

Genetic mutations and their expression lead to the impairment or abnormality of the bones in the middle or inner ear. A possible manifestation involves cochlear dysfunction. A review study from Cureoglu et al. revealed that the otosclerosis condition is located in the otic capsule, a dense bone surrounding the inner ear that lost its osteoclast function causing poor formation of collagen.⁵ Oftentimes, this condition also causes stapes, a bone in the middle ear, to be fixated.⁶ This condition is when the stapes bone of the middle ear becomes fixed or stuck, preventing effective vibration, hence sound transmission to the inner ear.⁷ 

Otosclerosis manifestations

• Hearing loss: There are different types of hearing loss; conductive hearing loss: hearing loss due to dysfunction or abnormality of the outer and middle ear, and sensorineural hearing loss: hearing loss due to dysfunction or abnormality of the inner ear and beyond
• Tinnitus: Tinnitus is the perception of sound (sometimes boiling water, whistling, roaring, or buzzing) that is not caused by external stimuli.⁸ The vestibular system (involving the semicircular canals) of the ear allows us to maintain balance. Otosclerosis could cause abnormality in those areas as well, however, studies of this phenomenon are still considered novel. It is not easy to conclude otosclerosis as its clinical manifestation overlaps with numerous hearing conditions that could cause hearing loss

Diagnosis of otosclerosis 

• Audiometry, also known as “pure-tone testing”, is conducted in a sound-proof room and wearing headphones or earphones. The examiner will play different “beep” sounds at different pitches and frequencies, and the patient signals to them if they can hear the sound played by raising their hand or pressing a button. This allows evaluation of the air conduction in each ear, providing insight into the hearing condition⁹ 
• Computed tomography (CT) is a pictorial review of a CT scan on the temporal bone that reveals otosclerotic hypodense demineralised plaques¹⁰ 
• Magnetic resonance imaging (MRI) is used for patients with mixed, sensorineural hearing loss, or tinnitus, and allows screening through MRI before CT to identify and rule out inflammatory, tumoural, or auto-immune diseases in the inner ear structure including the vestibular nerve¹¹
• Tympanometry, and its graph tympanogram, are used to measure the tympanic membrane compliance and mobility, pressure of the middle ear, and the volume of the external ear canal. The device pushes air into the ear, and the person receiving the measurement would feel a progressive pressure building and releasing in the ear several times in a period¹² 

Hearing aids as a treatment option

Hearing aids are a good solution for mitigating the effects of otosclerosis like hearing loss. Even with its non-invasive nature, it allows amplification of sound, providing improvement in hearing function. However, in cases with severe hearing loss, a hearing aid could potentially fall short of benefiting the patient. 

There are many different types of hearing aids: 

• Behind the ear (BTE) or mini BTE: mild to profound deafness 
• In the ear (ITE): mild to severe deafness 
• In-the-canal (ITC) and completely-in-canal (CIC): mild to moderately severe deafness

An audiologist would determine the benefits and limitations of each hearing aid type, and its consideration and prescription are based on hearing tests and patient lifestyles. For ITE and ITC hearing aids, ear moulds are taken from the patient to personalise the production of the earmold part of the hearing aid. After assembling the tubing, hook, and device all together, the programming port is connected to the computer for adjustments in the device programming, allowing precise and fine-tuning of the programme performance. Regular checkups and maintenance on the device and hearing condition are recommended to prevent further deterioration. 

Patient education and support

It can be jarring and stressful to be imposed with worsening hearing conditions but counselling and psychological support from professionals can help with methods and the overall experience of coping with hearing loss. In addition, seeking support groups can also help with the feeling of community and understanding of difficult situations in facing adversities not limited to hearing loss and health scares. The general education of disabilities including deafness should also be promoted more. This would help destigmatise difficult conversations like discussing methods of accommodating disabilities or gain an overall understanding and compassion for people with disabilities. 

For individuals who require hearing aids and their families, the maintenance and care of hearing aids should be emphasised and taught. As hearing aids can be costly without subsidies, it is important to ensure that the state of the hearing aid is maintained in good condition to prevent damage and deterioration. An example of a good maintenance routine is the dehumidification of the hearing aid (especially in humid countries) every night to prevent water damage to the device. Batteries are regularly changed or replaced depending on the hearing aid type, and the person in charge of providing the hearing device should explain its procedure. With the ever-growing technological advancements, digital and smart hearing aids are also drastically developing. At the moment, there are digital apps that are accessible on smartphones to allow monitoring of the health and longevity of the hearing aid. These apps also allow personalised volume adjustment and noise reduction functions. These hearing aid devices also have connectivity features such as Bluetooth, acting as earphones. With the increased development of AI and machine learning applications, there will be further advancements in hearing aid technology and developments in otosclerosis research. 

Summary

Effective symptom management and prevention of additional hearing loss are critical components of early diagnosis and treatment of otosclerosis, which improves patient outcomes markedly. Since hearing aids are customised to each user's needs and enhance sound quality, they are essential for symptom management. While public education and knowledge of hearing loss conditions can lead to better resources and assistance, ongoing research and development in hearing aid technology and treatments is crucial for improving patient care. Improving the quality of life and hearing health of individuals impacted by otosclerosis requires providing them with comprehensive treatment and assistance.