Diplacusis: Understanding Double Hearing
Do you notice sounds echoing in your ears? Do you hear sounds at different pitches in each ear? You may be experiencing a condition known as “diplacusis”, or double hearing. Today we will discuss what diplacusis is, what causes it, and what can be done about it.
What is Diplacusis?
|Diplacusis (pronounced dip-lah-KOO-sis) is a hearing disorder where an individual perceives a single sound as different pitches in the two ears, most commonly known as “double hearing”. It can present as a secondary symptom of hearing loss. However, it also occurs in those with normal hearing.|
In people with normal hearing, the brain works to blend sounds signals from each ear, which we then perceive as one sound. The two ears work together as one unit. This means the two ears bring together different sets of information, but this information is combined and interpreted in the brain.
- A common analogy used to describe this process is our eyes working together to form one image, not two separate images from two eyes.
Individuals with diplacusis, cannot turn the two sets of information into a unit. Hence, they perceive two different sounds. Diplacusis is more commonly found in individuals with some form of hearing loss.
With some types of hearing loss, each ear will hear sounds differently. And so the brain will perceive them as “double sound”. Some people with hearing loss may hear a combination of different types of diplacusis.
The Different Types of Diplacusis
There are two major types of diplacusis.
“Diplacusis monauralis” refers to the perception of a single sound as two different sounds or tones in the same ear. This condition only affects one ear.
“Diplacusis binauralis” is the most common type of diplacusis. As the name suggests, this affects both ears. This describes a case where an individual would perceive a sound or tone differently in each ear.
There are subtypes to “diplacusis binauralis”:
- “Diplacusis echoica” refers to a phenomenon experienced by some individuals where they perceive the timing of the same sound source differently, this results in an echo sensation.
- Others with “diplacusis binauralis” perceive pitches differently, and this is known as “diplacusis dysharmonica”.
The Causes of Diplacusis
Diplacusis can occur for numerous reasons. Diplacusis is most often caused when hearing loss is worse in one ear than in the other (asymmetrical hearing loss) or when hearing loss is present in one ear while the other has normal hearing (unilateral hearing loss).
It can be a result of damage to the hair cells of the cochlear or trauma to the ears, this could be a result of noise-induced hearing loss, certain medications, autoimmune diseases, sudden hearing loss and head trauma. It could even be a result of physical obstruction in the ear canal, including having impacted ear wax, blockage in the sinuses, upper respiratory infections or allergies.
Diplacusis usually has a sudden onset. In some cases, diplacusis is temporary and will resolve on its own, or it can be a chronic condition. The duration of diplacusis is dependent on the cause. Sometimes it can be experienced alongside tinnitus (a ringing in the ears).
Diplacusis can be caused by a physical blockage in the ear, such as:
- Excess earwax
- Ear infection or glue ear (these may occur after a bad head cold or flu)
- Blocked sinuses or blocked eustachian tube (this is the tube that causes your ears to “pop” when you fly)
More commonly diplacusis is caused by some form of sensorineural hearing loss, which can be the result of:
- Noise exposure
- Aging (age related hearing loss is known as presbycusis)
- Medical conditions such as Meniere’s disease
- Medications that are toxic to the auditory system
- Trauma to the head
- Acoustic neuroma
Signs And Symptoms to Look Out For
There are other conditions that individuals may experience alongside diplacusis, however, this would depend on the cause of the diplacusis. Hearing loss is one of the most common causes of diplacusis, so it is no surprise that the comorbidities associated with diplacusis are relevant for individuals with hearing loss.
Tinnitus is a common comorbidity with diplacusis. Tinnitus is a condition where individuals experience sounds or noises in their ears or head when there is no physical sound present in the environment. This is a common secondary symptom of hearing loss.
Experiencing diplacusis and tinnitus can be frustrating to the individual, especially for those who are musically inclined and are tuned in to the perception of different pitches. It can severely impact the mood and attitude of the individual, especially if they need to rely on their hearing for the performance of the job or hobby.
Other Signs of Hearing Loss
As diplacusis often occurs due to some form of loss of hearing, it is useful to be able to recognise other signs of hearing loss. These can vary from person to person but can include:
- Needing the speaker to repeat themselves to understand what has been said
- Feeling as though people are mumbling and not speaking clearly
- Mishearing what is being said – thinking a person has said one thing when they have said something different
- Needing a louder volume on the TV than what others with normal hearing would prefer
- Commonly, being able to hear in quiet but not being able to hear in background noise
- Similarly, being able to hear one-on-one conversation but not being able to hear a conversation in a group
- Tinnitus (ringing in one or both ears)
Treatments for Diplacusis and Hearing Loss
The causes of diplacusis can vary amongst individuals, as mentioned previously, it can occur as a result of hearing loss from permanent damage to the hair cells of the inner ears, or it can be a result of temporary hearing loss from physical obstruction from impacted ear wax. As a result of the different causes, the treatment options for diplacusis differs and is treated on a case-by-case basis.
Regardless, it is important to visit your local accredited audiologist to undergo a comprehensive audiological assessment to determine the possible causes of diplacusis for yourself, including addressing any potential hearing loss, this would allow appropriate management to take place.
For example, hearing loss and diplacusis from the physical obstruction of the ear canal with excess wax can be easily treated by the audiologist or health care professional to address the diplacusis.
On the other hand, if the diplacusis is a result of permanent hearing loss from damage done to the hair cells of the inner ear, this could be addressed with appropriate amplification devices.
Schedule a Free Hearing Test
If you suspect you have some hearing loss that is causing double hearing, book a hearing assessment. This needs to be a full diagnostic test by an audiologist, rather than an automated hearing screening at a shopping centre or expo, as some conditions that can cause diplacusis will not be properly picked up on a screening type of hearing test.
In Australia, diagnostic hearing tests can be obtained with a Medicare rebate, or if you have a pension or DVA card under the Commonwealth Hearing Services Program (HSP) voucher funding. Once the cause and extent of any hearing loss have been identified, the correct type of treatment can be recommended.
If the cause is a physical blockage such as wax, the diplacusis will often go away as soon as the blockage is removed. This should be done under medical supervision using ear drops, syringing or suctioning. Home removal using earbuds should never be attempted as this can potentially damage the eardrum and may even make the issue worse.
Diplacusis caused by an ear infection or blocked sinuses may also go away once the blockage is removed, but this may involve seeing an Ear, Nose and Throat (ENT) specialist, who can give expert advice and treatment.
If the cause of the diplacusis is determined to be a sensorineural hearing loss, then hearing aids will often assist in overcoming or reducing the double hearing as well as the communication difficulties associated with hearing loss.
Hearing aids come in a wide variety of styles and technology levels and consequently have a wide range of prices, so it is important to consult with an independent audiologist to find the right option for you. If you have a pension or DVA card, there are hearing aid options that are fully covered under the Commonwealth HSP voucher system.
Double Hearing with Hearing Aids
Sometimes people who wear hearing aids will experience echoey or lispy speech when the hearing aids are worn, but not once they take the hearing aids out. This is not diplacusis – in diplacusis, the echo would be the same or worse once the hearing aids were taken out.
This echoey sound quality often occurs in the first few weeks of hearing aid use, as your ears and brain get used to hearing sounds they haven’t heard for a while because of your hearing loss. This normally gets better once you have worn your hearing aids consistently for a month or two.
If you have had your hearing aids for longer than this and are still experiencing an echoey sound quality, it may be that the hearing aids have an electronic fault that requires repair, or that the hearing aids are not set properly or need fine-tuning. In this case, you should contact the audiologist who fitted the hearing aids for you for follow-up service.
Musicians And Double Hearing
- Up to 5 percent of musicians report diplacusis, compared to 1 percent of the general population.
Musicians report higher rates of diplacusis for two reasons. They are often exposed to higher levels of noise which can cause hearing loss. This is why the use of proper ear protection (such as custom-made musicians’ earplugs) is so important.
Secondly, musicians have trained themselves over time to notice slight differences in timing and pitch more easily than other people, so if they do experience hearing loss or double hearing, it is often more disruptive or disturbing to them.
Musicians may need customised treatment to address diplacusis, especially if part of the recommended treatment involves wearing hearing aids. The hearing aids may need specialised programs to allow for the precise hearing of the slight changes in pitch or volume that are important in music.
In a Nutshell
In summary, diplacusis can be a distressing experience for an individual, no matter which type of diplacusis or duration. Whilst diplacusis can have a variety of causes, it is often treatable. The treatment for diplacusis varies depending on the cause.
In most cases, individuals with diplacusis have some type of hearing loss or trauma to the ears.
It is crucial to seek help from an accredited audiologist who can provide a diagnostic hearing assessment.
Attune Hearing was built on a medical foundation and has been providing Australians with specialised hearing care and diagnostic hearing tests for more than 20 years. With us, your hearing is in great hands! To find a clinic near you, check out our location guide!