Quantification of Visually Evoked Cortical Potentials in Individuals With Hearing Loss

This research is being done to determine whether a test that measures a "Visual Evoked Potential" can be used in a new way for individuals that have hearing loss. This test measures the participant's brain's response (so called "brain waves") to specific visual images. This study will help the investigators determine whether this test could be used to improve treatments for patients with hearing loss.

The "Visual Evoked Potential" measurement test is already used in the investigator's Neurology clinic at Dartmouth Hitchcock Medical Center for various conditions to measure "early" brain responses that occur in the first 1-2 seconds after a new cue. Our research aims to explore your brain's response just after that early 1-2 second period by looking at a specific response called the "P300". The P300 wave is a brain response to new or different images or sounds. A visual evoked P300 has not been studied in individuals with hearing loss.

The investigators will compare the results of this test to standard auditory tests, tests of cognitive function, and cochlear implant patient outcomes to explore how these factors can predict successful use of a hearing aid or cochlear implant.

Participants will schedule two appointments, at times convenient to the participant, to come to the testing clinic to complete the Visual Evoked Potential testing as well as the auditory test, cognitive/mood assessment battery, and sound quality survey included in this study.

The first research appointment will include a test of the participant's vision that involves looking at a chart on a wall and identifying appropriate letters. After this brief visual test, the participant will complete VEP testing.

For the VEP portion of the testing, participants will sit in a comfortable chair and have electrodes placed at several locations on their scalp. Electrodes are stickers that connect to a wire that connects to a computer. Electrodes do not break the skin or commonly cause any discomfort or harm. Participants will sit for approximately 1 hour and watch images presented to them on a computer screen while the participant's brain's response is measured using a computer. A picture of the electrodes on the participant's head will be taken for precise electrode localization.

The second research appointment will consist of an auditory test, a cognitive/mood assessment, and a cochlear implant sound quality survey. The survey will only be completed by participants with a cochlear implant. The auditory testing portion will take place in the Audiology clinic and requires participants to listen and respond to different patterns of sound. While participants are at the clinic for testing, they will be asked to complete several questionnaires that ask about participant's mood and thought processing. Participants with cochlear implants will also be asked to complete a questionnaire about their perceived sound quality with their implant(s).

The Visual Evoked Potential measure, auditory test results, cognitive/mood assessment, and cochlear implant sound quality survey responses will be compared between "hearing loss" and "normal hearing" groups to determine if VEP testing can be used in a new way to predict successful use of a cochlear implant or hearing aid.

Eligibility Criteria:
Inclusion

* Subjects will be recruited from the Otolaryngology/Audiology clinic at DHMC with the goal of enrolling subjects with a variety of degrees of hearing loss and central auditory processing dysfunction.
* Age \> 18 y/o.
* Current and new patients receiving care in the DHMC Otolaryngology clinic or from the employees of Dartmouth College, DHMC, and the community, will be included as allowed under COVID guidelines.

Exclusion

* Patients with known brain pathology (e.g., CNS tumors, CVA diagnosis, etc...) will be excluded.
* Patients with severe neurological or neuropsychological disorders will be excluded.
* Patients with known seizure history will be excluded.
* Patients with known blindness will be excluded.
* The following special populations will not be included:
* Adults unable to consent
* Individuals who are not yet adults (infants, children, teenagers)
* Prisoners