A Northwestern University study on Diplacusis

 

Lauren Ervin is a current graduate student working towards her Master’s in

Communication Disorders at Northwestern University. Her current research is focused

on the phenomenon of diplacusis (or false pitch perception) and its effects on the

musician population.

 

Lauren Ervin

Her previous academic experience includes a Bachelor of Science at Western Kentucky

University (Bowling Green, KY) where Lauren studied Speech-Language Pathology.

Additionally, though she transferred during her sophomore year, Lauren also studied

Theatre and Creative Writing at David Lipscomb University (Nashville, TN).

Diplacusis (also spelled Dyplacusis for our Latin scholars) is a pitch perception problem.   There are many sources of diplacusis ranging from inner ear (cochlear) pathologies to neural issues relating to the brain and how sound is processed.

Extremely good pitch perception is sometimes referred to as Absolute or Perfect Pitch and, depending on the study, can be pitch perception that is within 1% of the target to as much as 5%.  Understandably the prevalence is not well-defined, both related to its relatively rare occurrence and the definition used.

As far as the cochlear sources of diplacusis, this can occur whenever there is significant inner hair cell damage, meaning that cochlear-related diplacusis doesn’t generally rear its ugly head until someone has at least a moderate sensori-neural hearing loss.  There are some data suggesting that depending on the chemotherapy used to fight cancer, there can also be significant inner hair cell damage with a relatively good audiogram.

For cochlear-related diplacusis, based on the work of Hallowell Davis in the late 1940s, music tones are perceived as being slightly flat (rather than sharp) for a typical high frequency sensori-neural hearing loss.   For those with a reverse slop audiogram such as that related to Meniere’s Disease, diplacusis would manifest itself as musical tones that are perceived as being slightly sharp.

Less is known about neural etiologies of diplacusis, and depending on where, and the extent of neural involvement, diplacusis may be perceived as being sharp or flat.

Lauren is hoping to study this elusive phenomenon in more detail.

If you are at least 18 years old, consider yourself musically inclined, and are currently experiencing difficulty struggling to stay on pitch where even the “right” notes sound “wrong”, you (and Lauren) may find this survey to be of great interest.

Interested people should contact Lauren Ervin at Laurenervin2019@u.northwestern.edu.

About Marshall Chasin

Marshall Chasin, AuD, is a clinical and research audiologist who has a special interest in the prevention of hearing loss for musicians, as well as the treatment of those who have hearing loss. I have other special interests such as clarinet and karate, but those may come out in the blog over time.

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