Overview of the Hannover Program Using the Nucleus Device

Successful implantation of a cochlear implant requires a healthy auditory nerve. Subjective and qualitative data can be obtained by means of promontory testing (PT). Cochlear microphonics (CM) in electrocochleography, on the other hand, gives information about the status of the hair cells in the inner ear. The results of both tests together can indicate the feasibility of an implant in cases of sensory deafness (PT positive, no CM), while other combinations help to localize the origin of the deafness, eg, neural or sensorineural. Therefore, the reliability of results is extensive and almost doubly guaranteed. To answer the question of using single-channel or multichannel cochlear implants we decided to use the 22-channel Nucleus device. The digital working system consists of the implanted receiver-stimulator and external speech processor. To date we have implanted 14 patients. In all of them, the electrode array could be inserted easily, and the threshold and comfortable levels could be adjusted very fast. The dynamic range showed a growth in the first weeks after the operation. Results of 11 of our patients are presented. They show that 1) speech-tracking scores with the processor are much higher than with lipreading only; 2) lipreading ability remains constant; 3) the understanding of vowels and consonants with the speech processor is much better; and 4) three of our patients reached scores between 20 and 30 words per minute with hearing alone for speech tracking.