The purpose of this study is to evaluate the safety and efficacy associated with the
provision of acoustic and electric sound processing to individuals who demonstrate
significant residual low-frequency hearing and profound high-frequency (above 1500 Hz)
sensorineural hearing loss. Delivery of acoustic-electric stimulation will be provided by
the Nucleus Hybrid L24 cochlear implant system.
1. Eighteen years of age or older at the time of implantation.
2. Severe to profound (a threshold average of 2000, 3000, & 4000 Hz > 75dB HL)
sensorineural hearing loss for frequencies > 1500 Hz. Low-frequency thresholds up to
and including 500 Hz should be no poorer than 60 dB HL.
3. Consonant Nucleus Consonant (CNC) monosyllabic word recognition score (mean of two
lists) between 10% and 60%, inclusive (i.e., 10% <= score <= 60%), in the ear to be
4. CNC word recognition score in the contralateral ear equal to, or better than, the ear
to be implanted but not more than 80%.
5. English spoken as a primary language.
1. Duration of severe-to-profound hearing loss greater than 30 years.
2. Congenital hearing loss (for the purpose of this study, onset prior to 2
3. Medical or psychological conditions that contraindicate undergoing surgery.
4. Ossification or any other cochlear anomaly that might prevent complete insertion of
the electrode array.
5. Conductive overlay of 15 dB or greater at two or more frequencies, in the range 250
to 1000 Hz.
6. Hearing loss of neural or central origin.
7. Diagnosis of Auditory Neuropathy.
8. Active middle-ear infection.
9. Unrealistic expectations on the part of the subject, regarding the possible benefits,
risks, and limitations that are inherent to the surgical procedure(s) and prosthetic
10. Unwillingness or inability of the candidate to comply with all investigational
11. Additional handicaps that would prevent or restrict participation in the audiological