In the past patients with profound high frequency hearing loss but mild to moderate low frequency hearing loss are often not considered for cochlear implant as there are still substantial amount of low frequency hearing left. This group of patients often end up using high power hearing aids. Even with hearing aids on this group of patients are still unable to achieve speech understanding especially in noisy situations. One possibility for this lack of amplification benefit is the presence of cochlear dead regions.

The remarkable outcome for those with cochlear implant has made this group of “less profound” patients to be considered for cochlear implant. However the decision to undergo conventional cochlear implant often means that the residual acoustic hearing will not be available anymore due to the insertion of the electrode array into the cochlea. A new cochlear implant technology has been developed by combining electrical stimulation (cochlear implant) and acoustic amplification (hearing aid amplification) for this group of patients. By using a shorter and more flexible electrode it allows electric stimulation of the basal cochlea for high frequency information without damaging apical cochlear structures that transmit low frequency acoustic information.

Patients with potential useful low frequency hearing loss but significant losses in the mid to high frequencies can now benefit from both cochlear implant and digital hearing aid technologies without damaging the residual hearing.