Using Anatomy-Based Fitting to Reduce Frequency-to-Place Mismatch in Experienced Bilateral Cochlear Implant Users: A Promising Concept

Fitting cochlear implant (CI) users can be challenging. Anatomy-based fitting (ABF) maps may have the potential to lead to better objective and subjective outcomes than conventional clinically based fitting (CBF) methods. ABF maps were created via information derived from exact electrode contact positions, which were determined via post-operative high-resolution flat panel volume computer tomography and clinical fitting software. The outcome measures were speech understanding in quiet and noise and self-perceived sound quality with the CBF map and with the ABF map. Participants were 10 experienced bilateral CI users. The ABF map provided better speech understanding in quiet and noisy environments compared to the CBF map. Additionally, two approaches of reducing the frequency-to-place mismatch revealed that participants are more likely to accept the ABF map if their electrode array is inserted deep enough to stimulate the apical region of their cochlea. This suggests an Angular Insertion Depth of the most apical contact of around 720 & DEG;-620 & DEG;. Participants had better speech understanding in quiet and noise with the ABF map. The maps' self-perceived sound quality was similar. ABF mapping may be an effective tool for compensating the frequency-to-place mismatch in experienced bilateral CI users.

Automated summary

Anatomy-based fitting (ABF) maps are potentially more effective than conventional clinically based fitting (CBF) methods for cochlear implant (CI) users. ABF maps were created using information from exact electrode contact positions determined by high-resolution computer tomography and clinical fitting software. In a study involving 10 bilateral CI users, the ABF map provided better speech understanding in quiet and noisy environments compared to the CBF map. Participants were more likely to accept the ABF map if their electrode array stimulated the apical region of their cochlea. The self-perceived sound quality with the ABF map was similar to the CBF map. ABF mapping may be an effective tool to compensate for frequency-to-place mismatch in experienced bilateral CI users.