Cochlear implants could help those deaf in one ear hear better in noise

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: • Individuals 18 years or older (Group A) Ear to be Implanted: Severe sensorineural hearing loss (HL) defined as: Pure-tone average at 0.5, 1, 2, 4 kHz \>80 dB HL ; Aided Consonant-Nucleus-Consonant Test (CNC) score ≤5% and Normal Hearing Ear: Normal or near normal hearing defined as an average of (0.5, 1, 2, 4kHz) ≤ 30 dB HL • Children 5 years to 17 years, 11 months (Group B) Ear to be Implanted: Severe sensorineural HL defined as: Pure-tone average at 0.5, 1, 2, 4 kHz \>80 dB HL; Aided CNC score ≤5% and Normal Hearing Ear: Normal or near normal hearing defined as an average of (0.5, 1, 2, 4kHz) ≤ 30 dB HL * Previous experience with a current conventional treatment option for unilateral \[SSD\] HL (HA, bone-conduction device, or CROS technology), if no previous experience a minimum trial period of two weeks is required * English spoken as a primary language * Willing and able to provide written informed consent Exclusion Criteria: * Ossification, abnormal cochlear nerve or any other cochlear anomaly that might prevent complete insertion of the electrode array * Previous cochlear implantation * Hearing loss of neural or central origin, including auditory neuropathy * Duration of profound sensorineural HL \>10 years per self-report * Active / chronic middle-ear infection; conductive HL in either ear * Medical or psychological conditions that contraindicate undergoing surgery as determined by the Investigator * Unrealistic expectations on the part of the participant/family, regarding the possible benefits, risks, and limitations that are inherent as determined by the Investigator * Evidence of and/or suspected cognitive or developmental concern * Unable or unwilling to comply with the requirements of the clinical investigation as determined by the Investigator * Investigator site personnel directly affiliated with this study and/or their immediate families; immediate family is defined as a spouse, parent, child or sibling * Cochlear employees or employees of Contract Research Organizations (CROs) or contractors engaged by Cochlear for the purposes of this investigation * Pregnant or breastfeeding women * Currently participating, or participated within the last 30 days, in another interventional clinical investigation/trial involving an investigational drug or device.