Profound mixed hearing loss: bone-anchored hearing aid system or cochlear implant?

OBJECTIVES

We evaluated 5 patients who were changed over from a Baha Cordelle to a cochlear implant (CI). Moreover, the level of phoneme score was determined at which a Baha Cordelle user was better helped with a CI.

METHODS

We offer descriptive case reports and a retrospective evaluation of speech recognition in Baha Cordelle users and CI users.

RESULTS

In the CI users with noncompromised cochleas, the 10th percentile of the aided phoneme score in quiet at 65 dB sound pressure level (PS65) was 42%. We consider this PS65 as the cutoff level for switching from a Baha Cordelle to a CI. When patients with mixed hearing loss were using the Baha Cordelle, the PS65 of 42% was obtained at a mean sensorineural hearing loss component of about 70 dB hearing level (HL). This 70-dB HL component was used to consider Baha Cordelle users for cochlear implantation. The results of the 5 patients support these transition criteria.

CONCLUSIONS

A CI is a valuable option in patients with mixed hearing loss when the sensorineural hearing loss component exceeds 70 dB HL or when the PS65 with a Baha Cordelle is less than about 40%. In such patients, the implantation procedure should be individualized on the basis of the clinical findings in the middle ear and mastoid cavity.