Evaluation of noise-canceling strategies used in the oticon medical neuro cochlear ımplant systems

Abstract

Objective: Oticon Medical cochlear implant (CI) systems were evaluated for noise reduction effectiveness using voice track (VT) and adaptive directional microphones to determine the optimum CI fitting parameters, especially in noisy environments. Methods: Ten CI users (3 females, mean age 28.22; 7 males, mean age 36.71) participated in the study. Speech recognition in noise was evaluated in different test conditions with 2-syllable word lists in stationary speech-shaped noise. Five different test conditions were determined for each participant using a combination of software-based VT and directional microphone technology. In the first condition, the omnidirectional microphone (M) was selected and VT was turned off. The fully directional M and strong VT combination were activated in the second condition. In the third condition, the omnidirectional M and strong VT were set. In the fourth condition, automatic adaptive directional M and medium VT were used. Finally, omnidirectional M and medium VT were selected. Results: Speech comprehension scores obtained in a quiet environment were significantly better than those of the other 4 conditions in a noisy environment (P < .01). In addition, the best noise comprehension score (44%) was obtained in the fourth condition, although this was not statistically significant (P < .05). Conclusion: The VT technology was more effective in understanding speech in noise when used in the medium setting and with an automatic adaptive directional microphone.