Hybrid 10 clinical trial: preliminary results.
Acoustic plus electric (electric-acoustic) speech processing has been successful in highlighting the important role of articulation information in consonant recognition in those adults that have profound high-frequency hearing loss at frequencies greater than 1500 Hz and less than 60% discrimination scores. Eighty-seven subjects were enrolled in an adult Hybrid multicenter Food and Drug Administration clinical trial. Immediate hearing preservation was accomplished in 85/87 subjects. Over time (3 months to 5 years), some hearing preservation was maintained in 91% of the group. Combined electric-acoustic processing enabled most of this group of volunteers to gain improved speech understanding, compared to their preoperative hearing, with bilateral hearing aids. Most have preservation of low-frequency acoustic hearing within 15 dB of their preoperative pure tone levels. Those with greater losses (>30 dB) also benefited from the combination of electric-acoustic speech processing. Postoperatively, in the electric-acoustic processing condition, loss of low-frequency hearing did not correlate with improvements in speech perception scores in quiet. Sixteen subjects were identified as poor performers in that they did not achieve a significant improvement through electric-acoustic processing. A multiple regression analysis determined that 91% of the variance in the poorly performing group can be explained by the preoperative speech recognition score and duration of deafness. Signal-to-noise ratios for speech understanding in noise improved more than 9 dB in some individuals in the electric-acoustic processing condition. The relation between speech understanding in noise thresholds and residual low-frequency acoustic hearing is significant (r = 0.62; p < 0.05). The data suggest that, in general, the advantages gained for speech recognition in noise by preserving residual hearing exist, unless the hearing loss approaches profound levels. Preservation of residual low-frequency hearing should be considered when expanding candidate selection criteria for standard cochlear implants. Duration of profound high-frequency hearing loss appears to be an important variable when determining selection criteria for the Hybrid implant.
Gantz
Bruce J
BJ
Department of Otolaryngology - Head and Neck Surgery, Iowa Cochlear Implant Clinical Research Center, University of Iowa, Iowa City, Iowa 52242-1078, USA. bruce-gantz@uiowa.edu
Hansen
Marlan R
MR
Turner
Christopher W
CW
Oleson
Jacob J
JJ
Reiss
Lina A
LA
Parkinson
Aaron J
AJ
D000161:Acoustic Stimulation; D000328:Adult; D003054:Cochlear Implants; D003131:Combined Modality Therapy; D004558:Electric Stimulation; D006309:Hearing; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000601:surgery* / Q000628:therapy*; D006801:Humans; D007484:Iowa; D010865:Pilot Projects; D013067:Speech Perception