The purpose of this study is to evaluate the long-term safety and efficacy of the Esteem® Hearing Implant in subjects suffering from moderate to severe hearing loss.

The Post Approval Study is an extension of the pivotal clinical trial, which was designed as a prospective, multi-center, non-randomized, clinical trial to evaluate the safety and efficacy of the Esteem® System. For this trial the subject acts as his or her own control.

This trial has been designed to meet the United States' regulatory requirements.

The subjects included in this study include the 57 subjects implanted under the original Investigational Device Exemption (IDE) study and the five (5) subjects implanted under the continued access expansion approved by the FDA. Of these 62 subjects, all but one (explant) were available for continued follow-up. These subjects were re-consented for the 5 year Post Approval Study. No new subjects were enrolled and implanted in this study. The goal was to monitor a minimum of 45 subjects through their five (5) year follow-up. Ultimately, 51 subjects completed the study.

The following questions are to be answered:

• Is the Esteem effective through 5 year follow-up?
• Is the Esteem safe through 5 year follow-up?

Inclusion Criteria:

Subject must meet all of the following criteria to be eligible for treatment in the trial:

1. Subject is at least 18 years old

2. Subject understands the nature of the procedure and has signed the Subject Informed Consent Form prior to the procedure

3. Subject is willing and able to comply with specified follow-up evaluations and understands the audiological test procedures and use of the Esteem® System.

4. Subject has moderate to severe sensorineural hearing loss between 500 and 4000 Hz in the ear to be implanted with pure tone air-conduction threshold levels within the limits of a Hearing Aid (HA) as follow:

   Freq (Hz) 500 1000 2000 3000 4000 Lower Level (dB HL) 30 35 35 35 35 Upper Level (dB HL) 100 100 100 100 100

5. Subject's air-bone gap is no greater than 10 dB at 4 of the 5 following frequencies: 500, 1000, 2000, 3000 and 4000 Hz.

6. Subject has an unaided maximum word recognition score of greater than or equal to 40% with recorded delivery using a phonetically balanced word list at Speech Reception Threshold (SRT) + 40 dB or at maximum tolerable presentation level.

7. Subject is a current user of a properly functioning and appropriately fit hearing aid. This is defined as the subject has used this aid for at least four (4) hours (average) per day (in the ear to be implanted) for at least three (3) months for a new aid or one (1) month for an adjusted aid.

8. Subject's hearing aid, in the ear to be implanted, shall appropriately fit optimally.

9. Subject has normally functioning eustachian tube

10. Subject has normal tympanic membrane

11. Subject has a normal middle ear anatomy

12. Subject has adequate space for Esteem® System implant determined via fine cut temporal bone CT scan

13. Subject is a native speaker of the English language.

14. Subject is a hearing aid user in the ear to be implanted

Exclusion Criteria:

Subjects will be excluded from the trial if any one of the following criteria is met:

1. Subject has a history of post-adolescent chronic middle ear infections, inner ear disorders or recurring vertigo requiring treatment, disorders such as mastoiditis, Hydrops or Meniere's syndrome or disease
2. Subject has a history of external otitis or eczema for the outer ear canal and the investigator believes this will affect the Esteem® System implantation
3. Subject has cholesteatoma or destructive middle ear disease
4. Subject has life expectancy of less than two (2) years due to other medical conditions
5. Subject has retrocochlear or central auditory disorders
6. Subject is known to be suffering from any psychological, developmental, physical, or emotional disorder that the investigator feels would interfere with the surgery or follow-up testing
7. Subject has a known history of fluctuating air conduction and/or bone conduction hearing loss over a one-year period of 15 dB in either direction at 2 or more frequencies (from 500 - 4000 Hz)
8. Subject has sudden hearing loss due to unknown cause
9. Subject has a history of disabling tinnitus, defined as tinnitus which required treatment.
10. Subject is unable to adequately perform audiological testing
11. Subject has a medical condition or undergoing a treatment that may affect healing and the investigator does not believe the subject is a good candidate for the trial.
12. Subject has diabetes that is not well controlled with medication or diet and the investigator does not believe in his best medical judgment that the subject would be a good candidate for the trial
13. Subject is pregnant at the time of device implant
14. Subject has a history of keloid formation
15. Subject has known hypersensitivity to silicone rubber, polyurethane, stainless steel, titanium and/or gold

Persons suffering from moderate to severe hearing loss that is sensorineural in origin

PAS phase through 5 years

All Adverse Events adjudicated by Clinical Events Committee

1. Study endpoints do not account for natural progression of hearing loss over 5-year follow-up.
2. Fitting methods for pre-implant hearing aid were not strictly controlled in the protocol.