Otosclerosis is a health condition in which abnormal bone remodelling in the temporal bone and otic capsule within the ear gradually interferes with hearing. The exact cause of this abnormal bone growth is not fully understood, but risk factors include family history, viral infections such as measles, environmental factors and hormonal influences.Â
In most cases, the abnormal bone changes begin around the stapes, one of the three tiny bones in the middle ear. When the stapes bone becomes fixed and cannot transmit sound vibrations properly, sound transmission through the middle ear bones is reduced, leading to conductive hearing loss. In some patients, the bone remodelling process can extend deeper into the inner ear and its structures, potentially causing sensorineural hearing loss (a permanent hearing loss) or a mixed hearing loss pattern.
Otosclerosis often affects both ears, although one side may be worse than the other. Hearing impairment usually develops slowly over years rather than days, which is why people with otosclerosis often do not realise how much their hearing has declined. Unlike other forms of hearing loss, otosclerosis is usually found in young to middle adulthood, between the ages of 20 and 45. Otosclerosis rarely causes total deafness, but it can lead to significant long-term hearing impairment if left untreated.
Broadly speaking, the types of otosclerosis can be understood by where the abnormal bone changes occur within the ear structures and the different effects that location has on the individual’s hearing.Â
The common form, in which abnormal hardening affects the stapes bone and stapes footplate, causes conductive hearing loss. Cochlear otosclerosis is a more advanced form of inner ear disease in which abnormal bone growth spreads through the otic capsule into the fluid-filled structures of the inner ear, potentially causing a mixed or sensorineural hearing loss pattern.Â
This distinction matters because it influences the choice between hearing aids, surgery, and, in advanced cases, cochlear implants.
Barrie Tan ENT Head & Neck Surgery provides comprehensive care for all types of otosclerosis.
If you believe you or a loved one has otosclerosis, contact us today so that we can start working on a plan towards better hearing.
The most common symptoms of otosclerosis are gradual hearing impairment and tinnitus. Symptoms of otosclerosis often include difficulty hearing whispers, softer speech or lower-pitched sounds. Some speak more quietly because their own voices seem unusually loud. These can be subtle signs of otosclerosis in the early stages.
Other symptoms of otosclerosis may include ringing in the ears, ear fullness, tinnitus, taste disturbances, dizziness, balance disturbances, or occasional vertigo. This happens more often when the bone disease process affects inner-ear structures beyond the stapes. Women with otosclerosis may notice temporary worsening during pregnancy, which is a useful clinical clue in some cases.
As the hearing loss is often gradual, the progression of otosclerosis can be easy to underestimate. A person may adapt by turning up the television volume, asking others to repeat themselves, or not noticing loud noises without realising that the hearing impairment is becoming more established. That slow pace is part of the reason why prompt diagnosis of otosclerosis is important, rather than simply ‘coping with it’.
You should see an ENT specialist if you notice gradual hearing loss, persistent tinnitus, or one ear becoming harder to hear than the other. Slow progressive hearing loss is particularly easy to dismiss, but a prompt diagnosis helps confirm whether the problem is otosclerosis or another cause with similar symptoms that may need a different treatment.
An ENT review is especially useful if hearing loss is affecting work, communication, confidence, and day-to-day safety. It is also important to assess for dizziness, balance symptoms, or unilateral change. In Singapore, specialist ENT evaluation is the usual next step when conductive hearing loss suggests stiffening of the middle ear bones, including the stapes.
The diagnosis of otosclerosis is based on the hearing history, physical examination, hearing tests, and, in many cases, CT imaging. Diagnosing otosclerosis starts with ruling out other conditions with similar symptoms, such as middle-ear fluid, chronic ear disease, ossicular problems, or other causes of progressive hearing loss. From there, formal testing can begin to understand the degree and type of the hearing loss.
An otosclerosis audiogram helps show the degree and pattern of the hearing loss across different frequencies. In many patients, it suggests a conductive loss pattern consistent with reduced stapes bone movement. An otosclerosis tympanogram assesses middle-ear sound conduction and supports the wider picture. Together, these hearing tests help an ENT specialist decide whether otosclerosis is likely and whether surgery may be helpful.
An otosclerosis CT scan is often requested when the hearing test pattern raises suspicion. Computed tomography (CT) imaging of the temporal bone and otic capsule can provide greater detail of ear structures, including the stapes, and help confirm the diagnosis or exclude other bone-related structural problems. This helps the specialist determine the next steps, whether it is hearing aids or a surgical procedure.
Dr Barrie Tan was the former Head of the Department of Otolaryngology (ENT) at Singapore General Hospital and has dedicated his career to improving his patients’ ear and hearing health and quality of life.
Non-surgical treatment for otosclerosis usually involves observation, medical therapy or hearing aids, depending on the severity of hearing loss and the patient’s needs. If the hearing loss is mild and not disrupting daily life, careful monitoring may be reasonable, especially if the patient is still functioning well.
Hearing aids remain one of the main treatment options for otosclerosis. For most patients, they are an effective first-line option for treating otosclerosis. Hearing aids amplify sound waves and can improve day-to-day communication without the need for an operation. They do not stop the bone disease process, but they can be an excellent way to manage symptoms, especially for people with otosclerosis who prefer not to have surgery or whose hearing loss is not yet severe enough to justify it.Â
Treating otosclerosis is centred on restoring hearing function and managing bone changes rather than curing the underlying condition. At present, there is no established drug treatment or medical therapy that reliably reverses otosclerosis or halts abnormal bone remodelling in body tissue. Exposure to loud noise should also be avoided, as it can worsen hearing difficulties in those with otosclerosis.
Otosclerosis surgery can improve hearing by bypassing the fixed stapes bone with a prosthetic device. The surgical procedure is called a stapedotomy or stapedectomy, often grouped together as a ‘stapes surgery’. During stapes surgery, the ear canal is used to access the middle ear, and the stapes footplate is the primary target bone. The aim is to restore the transmission of sound vibrations from the outer and middle ear bones to the inner ear, using a prosthetic device to replace or bypass the stapes.
This surgical procedure is usually considered when the hearing loss is significant enough to affect the quality of life and when the hearing test pattern supports the diagnosis of otosclerosis. If both ears are affected to the same degree, surgery is usually done on one ear at a time so the operated ear has time to heal before the other ear is considered.Â
In more advanced disease, especially when the inner ear bone structures are involved, and standard stapes surgery is unlikely to provide sufficient benefit, cochlear implants may need to be considered.Â
Recovery after stapes surgery is usually manageable, but patients should understand both the likely aftercare and the limits of this surgical procedure. Most patients go home after one night in the hospital. After the operation, water precautions are important, and patients are usually advised to avoid heavy lifting, straining and forceful sneezing for at least a month while the ear and inner ear structures heal.
Like any ear operation, otosclerosis surgery is not risk-free. The facial nerve runs near the surgical site and must be carefully identified during the bone work to avoid damage. For some, the sense of taste can be disrupted due to the facial nerve and nearby ear structures. In rare cases, hearing loss may persist after the surgical procedure, and the outcome for the operated ear may not match the patient’s expectations. The right decision depends on the degree of hearing loss, the condition of the other ear, the patient’s lifestyle and expectations, and whether hearing aids provide sufficient benefit.
In most cases, the prognosis for otosclerosis is favourable, as hearing can usually be improved or managed effectively, even if it is diagnosed at a later stage when the bone changes are more advanced. The longer-term outlook depends on the rate of otosclerosis progression, whether one or both ears are affected to the same degree, and whether the disease remains limited to the stapes bone or extends further into the inner ear. Otosclerosis may progress over a lifetime in some patients, requiring ongoing management with hearing aids and the monitoring of hearing function.
Gradual hearing loss should not be ignored when effective treatment options for otosclerosis are available. If you have otosclerosis symptoms, or if otosclerosis has been diagnosed and stapes fixation has been confirmed, a specialist review can clarify the diagnosis and help you understand the most suitable next step.
At Barrie Tan ENT Head & Neck Surgery, otosclerosis is assessed carefully with hearing tests and, where appropriate, imaging, followed by a clear discussion of the pros and cons of hearing aids versus surgery. If you are concerned about hearing loss, tinnitus, or the possibility of otosclerosis, contact our clinic to arrange a consultation with ENT specialist Dr Barrie Tan.
MBBS, MRCS (Edinburgh), MMed (Otorhinolaryngology), FAMS
Dr Barrie Tan is an ENT specialist at Gleneagles Hospital, Singapore, with more than 20 years of clinical and surgical experience. He previously served as Head of ENT and Director of the Centre for Hearing and Ear Implants at Singapore General Hospital. The information provided is not intended as medical advice. More about our medical experts.
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