Diplacusis: Understanding 'double' hearing

For most people, our ears work in tandem, delivering sounds as one "unit" to our brain. Even if the ears perceive slightly different pitches, our brain still can interpret it as the same source of sound. This is similar to how our eyes work—we see one visual field, instead of two. 

Yet, for some people, the ears don't interpret noises as a single sound, and they instead experience a condition known as diplacusis.

What is double hearing?

Diplacusis is a form of hearing loss that causes our ears to hear sounds so differently it creates a disturbing two-sound experience.

In more medical terms, diplacusis is the “perceptual anomaly whereby the same sound is perceived as having a different pitch depending on whether it is presented in the left or the right ear," according to a 2016 study.

As you can imagine, this sensation, often called "double hearing," can be disturbing and troubling to those who experience it. It can affect anyone, but is most common among people who have hearing loss in one ear, or are starting to lose their hearing. 

Types of double hearing

Double hearing can occur in both ears or it can affect just one ear, which is known as diplacusis monauralis. More commonly, though people notice a problem with both ears, known as diplacusis binauralis. 

When you hear the same sound differently in each ear, it's usually related to pitch or timing. One ear may hear a sound at a different pitch and speed than the other ear. 

Two main types of diplacusis

There are two subtypes of diplacusis binauralis:

• If you don't have problems with timing, and it's mostly different pitches you struggle with, it's a subtype known as diplacusis dysharmonica. This is the most common type of diplacusis.
• When ears hear sound at different speeds, it's a subtype known as diplacusis echoica. Because your ears are hearing things at different times, you may hear the same sound repeated as an echo.

What causes diplacusis?

Those who develop diplacusis usually notice it suddenly after exposure to loud noise, a bout with an ear infection or trauma to the head. As you can imagine, musicians notice this condition more readily than non-musicians as their ears are more sensitive to pitch and tone.

In addition to double hearing, people with diplacusis may also develop tinnitus, a ringing or buzzing noise, in the affected ear. Some people with Meniere's disease also may struggle with double hearing. 

Diplacusis can be caused by wear and tear to the inner ear's delicate hair cells as the result of:

• Noise-induced hearing loss (NIHL)
• Trauma to the head
• Certain medications
• Autoimmune disorders including low thyroid hormones
• Age-related hearing loss

Diplacusis also can be caused by an obstruction in the ear because of:

• Ear infection
• Clogged ears or sinuses from a respiratory infection or allergies
• Excess earwax
• Tumor, such as acoustic neuroma

Can you treat double hearing?

If your diplacusis is caused by an obstruction, your hearing may return to normal once the obstruction is removed or the infection subsides. Diplacusis caused by sensorineural hearing loss is permanent, but it may be treated with hearing aids or cochlear implants. Auditory rehabilitation and/or auditory training can also help your brain adapt. 

How to get help for diplacusis

If you notice symptoms of diplacusis or suspect you are losing your hearing, promptly make an appointment to see a hearing healthcare professional.

They can provide easy, painless testing and determine the right course of action. Visit our directory of consumer-reviewed hearing clinics to find a hearing aid specialist or audiologist near you.