Patient case (clinical description): A 50-year-old woman comes to the clinic with intermittent ear discharge and sense of hearing loss on her left ear.  Past medical history is significant for obesity, hyperlipidemia, and diabetes mellitus.  Her medications include Metformin, Atorvastatin and Vit D supplement. Vital signs are normal. BMI is 37. Otoscopy shows a small perforation in the left tympanic membrane and a pearly mass behind the membrane.  Conduction hearing loss is noted in the left ear.  The remainder of the ear, nose, and throat examination is normal.

Patient's own account: I went to the clinic the other day because I had some fluid in my ear and I felt like I could not hear as well as I used to in my left ear. I'm a 50-year-old woman, and I have been obese for a while now. I have diabetes and cholesterol. I take some medication. I take metformin, atorvastatin, and vitamin D supplements. When I was admitted, my vitals were normal. My BMI is 37. When they looked into my ears, they said that my left tympanic membrane was broken and there was some fluid behind the membrane. During the hearing test, they could assess that my left ear suffers from hearing loss. They also performed ear, nose, and throat examinations that turned out to be normal.

Clinical trial: Deep Phenotyping of Hearing Instability Disorders: Cohort Establishment, Biomarker Identification, Development of Novel Phenotyping Measures, and Discovery of Therapeutic Targets

Eligibility criteria:
-  INCLUSION CRITERIA:

        In order to be eligible to participate in this study as a subject with HI, an individual
        must meet all of the following criteria:

          1. Provision of signed and dated informed consent.

          2. Stated willingness to comply with all study procedures and availability for the
             duration of the study

          3. All genders, aged 18-65 years

          4. Diagnosed with hearing instability, defined as documented hearing instability on
             serial audiometry with sensorineural hearing loss (SNHL) greater than 30 dB HL at one
             or more frequencies (Jose A. Lopez-Escamez et al., 2015) on at least one hearing test.
             Inclusion will require documentation of clinically significant change in hearing
             (either worsening or improvement) between at least 2 hearing tests or documentation of
             a sudden change in hearing. Clinically significant change in hearing will be defined
             by a change of 10 dB at any three frequencies, 15 dB at any two frequencies, or at
             least 20 dB at one frequency. A sudden change in hearing will be defined as at least a
             30 dB difference at 3 consecutive frequencies in the affected ear as compared to the
             contralateral ear (Chandrasekhar et al., 2019).

          5. No air-bone gaps in excess of 10 dB for 500-4000 Hz indicative of conductive HL.

          6. Normal middle ear function as indicated by normal 226 Hz tympanograms bilaterally,
             defined as middle ear pressure between plus minus 100 decaPascals, and peak
             compensated static compliance between 0.3-1.5 milliliters (Margolis & Heller, 1987)

          7. For females of reproductive potential: Negative pregnancy test at start of study

        EXCLUSION CRITERIA:

        An individual who meets any of the following criteria will be excluded from participation
        in this study:

          1. Presence of non-MRI compatible devices (cardiac pacemaker, meta<specific devices
             (e.g., cardiac pacemaker)

          2. Pregnancy or lactation

          3. Known allergic reactions to gadolinium

          4. Febrile illness within 2 weeks that could affect immune profiling*

          5. Evidence of active outer or middle ear disease or anomaly (e.g. otitis media, stenotic
             ear canal, otorrhea)

          6. History of chronic, as defined by fluid in the middle ear for more than 4 months, or
             recurrent otitis media, as defined by more than 4 episodes of acute otitis media in
             one year.

          7. Current PE tubes

          8. Bilateral profound (Pure tone average (PTA) > 90 dB HL) sensorineural hearing loss

          9. History or diagnosis of a central nervous system disorder, including but not limited
             to:

               1. Intracranial tumors

               2. Cerebrovascular disease

               3. Degenerative CNS disorder

               4. CNS trauma

               5. Encephalitis

               6. Meningitis

         10. Unable to discontinue medications that can interfere with vestibular test results for
             the 48 hours immediately preceding a vestibular study session. These include any and
             all anti-dizziness medications (such as Antivert), alcohol, caffeine, prescription
             pain medications (such as Percocet), prescription headache medications (such as
             Imitrex), sleeping pills (such as Ambien), anti-seizure medications (such as Topamax),
             and/or antihistamines (such as Benadryl).

         11. Current diagnosis from the Diagnostic and Statistical Manual of Mental Disorders (DSM
             IV) of schizophrenia, bipolar disorder, or psychosis.

         12. Unstable intercurrent illness that in the judgment of the PI could prevent or confound
             collection of data. Prospective study subjects who are cognitively impaired and lack
             consent capacity, will not be enrolled.

               -  Participants suspected of having COVID-19 will be moved to the designated
                  COVID-19 unit and tested for SARS CoV-2 and Respiratory Pathogen Panel per
                  guidance from NIH CC Clinical Practice Safety Guidelines. Possible COVID-19
                  infections identified by phone screen will not be eligible for study protocol
                  until infection resolved.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 18 Years old.
Subject must be at most 65 Years

Eligibility (NLI label): Entailment