Safety and Efficacy of the Vibrant Soundbridge (VSB) for Mixed and Conductive Hearing Losses

Inclusion Criteria: * Adults, 18 years of age or older at time of implantation * English as the primary language * Appropriate motivation and expectation levels * Geographically and physically able to return to the investigational center for scheduled evaluations and follow-up appointments. * At least a 28-day unsuccessful hearing aid trial (within the past 24 months prior to enrolment). * Persons who after being informed that a different hearing aid than the one they currently have may provide improved hearing, still request an implant. * Ability to undergo general anesthesia * Audiological tests suggest either a conductive or mixed hearing loss. The non-implanted ear may fall outside these criteria; however, threshold levels may not be worse than severe sloping to profound. * Conductive Hearing Loss * Pure-tone bone-conduction threshold levels in the ear to be implanted shall fall at or within the levels stated below. There should be an air-bone gap of 15 dB HL or more at three or more of the frequencies 500, 1000, 1500, 2000, 3000, and 4000 Hz. Pure-tone air-conduction levels should indicate the presence of at least a moderate hearing loss of at least 41 dB HL. Air conduction levels are not limited on the upper end. * Upper Limits of Bone Conduction Thresholds for Conductive Hearing Loss Frequency (kHz) 0.5 1.0 1.5 2.0 3.0 4.0 Bone Conduction upper limit (dBHL) \<25 \<25 \<25 \<25 \<25 \<25 * Mixed Hearing Loss * Pure-tone bone conduction threshold levels in the ear to be implanted shall fall at or within the levels stated below. There should be an air-bone gap of 15 dB HL or more at three or more of the frequencies 500, 1000, 1500, 2000, 3000, and 4000 Hz. Bone conduction thresholds at least three of the frequencies should be 26 dB or greater. Pure-tone air-conduction thresholds should be, on average, at least moderately impaired of 41 dB or greater. Air-conduction levels are not limited on the upper end. * Lower and Upper Limits of Bone Conduction Thresholds for Mixed Hearing Loss Frequency (kHz) 0.5 1.0 1.5 2.0 3.0 4.0 Bone Conduction lower limit (dBHL) 0 0 0 0 0 0 Bone Conduction upper limit (dBHL) 45 50 55 65 65 65 * Good potential for aided speech recognition as indicated by a pre-operative monosyllabic word score of \> 30% in the ear to be implanted as measured under headphones at 40 dB SL or at MCL * Hearing aid trial with appropriately fitted hearing aids of at least 28 days duration within the past 24 months, unless the subject is unable to wear hearing aids for medical reasons * Most recent audiometric data, if available, judged to be of good test-retest reliability. Exclusion Criteria: * Hearing loss of purely sensorineural origin * Retrocochlear or central auditory disorders * Active middle ear infection * Tympanic membrane perforation, ears with previously reconstructed tympanic membranes may be included * Bone-conduction thresholds in the ear to be implanted that have demonstrated a recent fluctuation at two or more frequencies of 15 dB in either direction in the last 6 months, as demonstrated by serial audiograms. * History of post-adolescent, inner-ear disorders, such as vertigo or labyrinthitis * Chronic or non-revisable vestibular or balance disorders * Middle ear infections not responsive to medical treatment * Skin or scalp conditions that may preclude attachment of the Audio Processor or that may interfere with the use of the Audio Processor * Chronic pain in or around the head * Current or previous use of an active hearing implant in either ear. * Any known physical, psychological, or emotional disorder that may interfere with the completion of scheduled follow-up evaluations * Developmental delays or organic brain dysfunction