Diplacusis is a frustrating hearing condition. Also known as double hearing or interaural pitch difference (IPD), diplacusis binauralis occurs when a person hears the same sound differently in each ear. Usually, our brain distinguishes a single auditory stimulus as one sound, but with diplacusis, there is a dissonance in the pitch or timing of a sound, so one ear often hears the correct tone, while the other detects the pitch as either flat (lower) or sharp (higher). Hearing one sound as two often times can be disconcerting and frustrating for a person experiencing this. Unfortunately for some, this condition may only be temporary, but others may experience this effect permanently.
Generally a symptom of sensorineural hearing loss, there are a few different forms of diplacusis. The most common type is diplacusis dysharmonica, which is when one ear perceives a sound normally, but the other hears the pitch differently. With the second form, diplacusis binauralis, the same sound is heard differently in each ear. The pitch or timing could be different in each ear. Diplacusis monauralis is similar to diplacusis binauralis, but the two different sounds are heard in the same ear. The fourth and last is diplacusis echoica, which is when the timing of sounds are slightly off, creating an echo effect.
A symptom of sudden or bilateral hearing loss, diplacusis occurs when hearing loss is experienced in one ear, or when uneven hearing loss is experienced in both ears. Diplacusis is usually noticed after trauma, a severe ear infection, from taking certain medications, or after exposure to a dangerously loud noise. Sometimes an individual with diplacusis may also develop tinnitus, an undetectable buzzing or ringing noise in the affected ear. However, diplacusis could also be caused by an obstruction in the ear due to a tumor, clogged sinuses, excessive earwax, or from a sinus infection. Luckily, if diplacusis is present due to an obstruction, hearing can return to normal once the infection subsides or the obstruction is removed. Otherwise, treatment for diplacusis will vary depending on the underlying cause. However, when the condition is likely to be permanent, listening devices such as cochlear implants and hearing aids can help tremendously.
If you are noticing the signs and symptoms of diplacusis, don’t delay. Make sure you contact your hearing healthcare professional to make an appointment and get a full evaluation so they can provide you with the right course of action.