Patient case (clinical description): A 47-year-old woman comes to the clinic complaining of dizziness.  She also has occasional nausea and ringing in her right ear.  The patient also has difficulty hearing while holding her phone to the left ear, although hearing in her right ear is normal.  The dizziness improves spontaneously, and she feels fine between episodes.  Past medical history is notable for hypothyroidism and low vit D level, for which she is using Levothyroxine and Vit D pearl.  She does not use tobacco or drink alcohol. Physical examination shows sensorineural hearing loss in the left ear. She has only one-man sexual partner and menopaused 2 years ago.

Patient's own account: The other day, I had to go to the clinic due to severe dizziness. I'm 47 years old, and I've been suffering from nausea and ringing in my right ear. I also have difficulty hearing in my left ear while I hold my phone, even if my hearing in my right ear is normal. The dizziness just gets me all of a sudden but I don't have any symptoms in between 2 episodes. I suffer from hypothyroidism and low vitamin D levels. So I take Levothyrox and vitamin D pearl. I don't smoke or drink. They conducted a physical exam and said I had hearing loss in my left ear. My only partner is my husband, and I'm menopause for 2 years now.

Clinical trial: Single-sided Deafness and Cochlear Implants

Eligibility criteria:
Inclusion criteria: • Patients with acquired single sided sensorineural deafness due to
        cochlear damage.

          -  Age: 18-70 years old.

          -  Onset of SSD within 6 months to 10 years before Study inclusion.

          -  Normal hearing on the contralateral ear (Hearing thresholds 0.125-2 kHz 25 dB HL or
             better, 4-8 kHz 35 dB HL or better, 100% speech discrimination at 80 dB SPL).

          -  Regular middle ear function on the hearing ear.

          -  Regular structure of the cochlea and the cochlear nerve (as demonstrated by MRI, MRI
             scans are included in the basic assessment of SSD and are no study-specific
             investigations).

          -  Fluency in the German language.

          -  Subject is willing to comply with all study requirements.

          -  Impairment in daily life as a consequence of SSD (communication problems, annoyance by
             tinnitus perception).

          -  Subject is not participating in another ongoing research study related to the SSD.

          -  Subject does not have unrealistic expectations, regarding the outcome of the
             intervention.

          -  Subject has had a trial with conventional acoustic measures in SSD (CROSS, BAHA).

        Exclusion criteria: • Uncertainty of correct diagnosis of SSD.

          -  Retrocochlear cause of SSD (Deafness due to lesions of the acoustic nerve or central
             auditory pathways).

          -  Active middle ear infections.

          -  Ossification of the cochlear that prevents electrode insertion.

          -  Tympanic membrane perforation.

          -  Psychiatric comorbidities such as depression or cognitive deficits.

          -  Severe coexisting illness with a medium survival of less than 5 years.

          -  Exposure to radiation with a cumulative effective dose of 5 mSV within the last 5
             years (including the ongoing year).

          -  Increased risk profile for general anesthesia due to cardiovascular comorbidity.

          -  Metallic implants constituting an exclusion criterium for MEG procedures of the brain.

          -  Pregnancy (a pregnancy test will be performed in women in the reproductive age group
             before study enrolment and before postoperative PET scan) and lactation.
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 70 Years

Eligibility (NLI label): Entailment