Cochlear implants and tinnitus.

The clinical observation that multichannel intra-cochlear cochlear implants have a suppressive effect on tinnitus in profoundly deaf patients is supported by many published studies. Whilst there are problems with that literature, specifically in the way that tinnitus outcomes are reported, the finding of tinnitus benefit is consistent. New developments in this area include the use of functional imaging to investigate tinnitus suppression by cochlear implant stimulation and consideration of a reported worsening effect on tinnitus of binaural implantation. Following work on hearing aids, it is suggested that optimization of the benefit of monaural cochlear implantation on tinnitus in a tinnitus-specific electrode configuration might include the use of a low knee point compression algorithm and disabling directional microphone function: these strategies are potentially also of benefit in patients whose tinnitus results in sleep disturbance. Opportunities for stimulation strategies for tinnitus suppression that bypass speech processing are also identified.