An ossified cochlea can make it difficult, but not impossible, to do a cochlear implant in that ear. The presence of the bone can interfere with the putting of the electrodes into the cochlea, affecting either the insertion depth or the placement. To minimize this risk, sometimes the implantation timetable will be sped up if ossification is present.
Meningitis is not the only illness or condition that can lead to ossification. Autoimmune inner ear disease can also cause ossification.
Sources:
Cochlear implantation in the partially ossified cochlea. Julie Kerr, Douglas D. Backous. Operative Techniques in Otolaryngology - Head and Neck Surgery. June 2005 v16 i2 p113(4). - This article discusses how improved surgical techniques have made it possible to implant even with partially ossified cochleas.
Implantation of the Ossified Cochlea. Jennifer L. Smullen, Thomas J. Balkany. Operative Techniques in Otolaryngology - Head and Neck Surgery. June 2005 v16 i2 p117(4). - This article too, discusses how improved surgical techniques make it possible to implant in ossified cochleas.
Medicine.Net, http://www.medterms.com/script/main/art.asp?articlekey=10397
Baylor College of Medicine, http://www.bcm.edu/oto/grand/02_10_00.htm
Cochlear Implants. Susan B. Waltzman, Noel L. Cohen. Thieme, 2000.
