Diplacusis Explained: Understanding the Causes of “Double Hearing” Syndrome

For most of us, our ears work together, with the brain interpreting a single source of sound even if each ear picks up slightly different pitches. However, for some of us, the ears don't translate noises into a single sound; instead, we experience a condition called diplacusis.

What Is Diplacusis?

Hearing is an extremely complex process in which many fragile parts of the ear work together to send signals to the brain. If one were to consider a completely normal auditory system, the sound is picked up by the outer ear and then travels through the inner ear where the sound waves are converted into messages interpreted by the brain.

In regular-hearing people, information from the left and right ears seems to be interwoven into a single sound. Sometimes, however, a person's hearing just stops piecing them together, and they come across as two different noises.

Diplacusis is a condition, quite rare, whereby a person will hear exactly the same sound at different pitches in each ear. Double hearing, also known as interaural pitch difference, the sufferer will perceive dissonance in pitch or timing of a sound from one ear to the other.

In this condition, there is also the case wherein a sound can be perceived in two manners in relation to intensity, timbre, and tonality. It can cause mutilation in speech, music, and other forms of sound. Such dissonance can be quite very troublesome and irritating for the one experiencing it.

Double hearing can, however, appear in different forms. If it only affects one ear, the condition then is called diplacusis monauralis. On the other hand, diplacusis binauralis is when the problem with hearing is found in both ears.

There are actually two subtypes of diplacusis binauralis. Diplacusis dysharmonica refers to the condition wherein a person hears a sound in different pitches. Diplacusis echoica has a person hearing the same sounds at different speeds, often appearing like noises echo.

Causes and Treatments of Diplacusis

As with other ear diseases, the chances of treating diplacusis are associated with the treatment of its cause. At the first symptoms, it is recommended that individuals consult a specialized healthcare provider who will investigate what exactly leads to the disorder.

The likely cause of diplacusis can depend on the type of double hearing. Anybody may experience diplacusis, although there are several factors that might make a person more susceptible to it.

Hearing abilities could decline with aging or due to damage to the middle of the outer ear, especially when it disrupts transmission in sound waves to the inner ear. Exposure to loud noises may also harm the delicate structures in the inner ear and cause diplacusis. Other causes include infections in the ear and some medications, which have huge potential for destroying the auditory mechanism.

Obstruction-based diplacusis may return to normal hearing once the obstruction is removed or the infection has subsided, but sensorineural hearing loss is permanent. It can, however, be treated with hearing aids or cochlear implants. The brain also gets adapted with auditory rehabilitation or auditory training.

Correct diagnosis of the type of diplacusis is, therefore, of great importance in applying proper treatment. Diagnosis of double hearing must be performed with a thorough hearing test or examination by a properly trained hearing clinician.