Diplacusis

Diplacusis was first reported by George E. Shambaugh in 1907. The name originates from the Greek words diplous (double) and akousis (hearing), translating quite literally to double hearing. It is an auditory phenomenon whereby the affected individual hears the same, singular sound as two different pitches.

There are a few different types of diplacusis. Most commonly, the sound is heard at a different pitch in each separate ear, known as binaural diplacusis. However, occasionally the sound can be heard as two different pitches in the same ear, monaural diplacusis. While individuals with both normal hearing or hearing loss can experience it, those with hearing loss often experience it to a greater degree, particularly if the hearing loss is only in one ear (unilateral), or worse in one ear (asymmetrical). For some, diplacusis can be present from birth, and has been touted as the main cause of off-key, or tone-deaf singers. However, it can also be caused by things such as physical trauma to the ear, oto-toxic medications, or over-exposure to loud sounds such as noise or music.

From a musical perspective, it’s not hard to imagine how diplacusis can get in the way of things, influencing everything from pitching to intonation. For those affected it can lead to out of tune playing, a sense of detachment to the music, or feeling like you’re swimming in music without at key. Because of their acute sensitivity to pitch changes, musicians are often first to notice it. For instance, a vocal soloist once stopped mid-performance due to temporary diplacusis following an ear surgery!

We’ve dug deep online to find an example of what Diplacusis can sounds like. While it’s by no means an exact replica of what someone hear, and will be different for each individual, this was close to the experience some of our team have experienced. Jump to 2.11 minutes for the Detuned setting on this TC-Helicon Pedal:

If you believe that you’re experiencing diplacusis, speak to your GP and audiologist about your symptoms. It’s important to have your hearing tested and if you think sound over-exposure is related, take steps to protect them when it’s loud. If you are pursuing a career in music while experiencing it, take the time to lean into your other strengths as a performer, using your knowledge, intuition, even listening to the subtle physical differences each note creates. It’s by no means impossible, but takes creative determination to push through. We’ve got your back.

By Vivian Hoang

References

Albers, G. D., & Wilson, W. H. (1968). Diplacusis: Clinical Diplacusimetry. Archives Otolaryngology, 87, 61–68. http://jamanetwork.com/

Colin, D., Micheyl, C., Girod, A., Truy, E., & Gallégo, S. (2016). Binaural Diplacusis and Its Relationship with Hearing-Threshold Asymmetry. PLoS ONE, 11(8), 1–16. doi:10.1371/journal.pone.0159975

Jansen, E. J. M., Helleman, H. W., Dreschler, W. A., & Laat, J. A. P. M. (2009). Noise induced hearing loss and other hearing complaints among musicians of symphony orchestras. Int Arch Occ Environ Health, 82(2), 153–164. doi: 10.1007/s00420-008-0317-1

Knight, R. D. (2004). Diplacusis, hearing threshold and otoacoustic emissions in an episode of sudden, unilateral cochlear hearing loss. In J Audiol, 43(1), 45–53. doi: 10.1080/14992020400050007

Feature image by Kate Disher-Quill