Frequency reallocation based on cochlear place frequencies in cochlear implants: a pilot study

Abstract

Purpose The aim of this study is to evaluate speech perception outcomes after a frequency reallocation performed through the creation of an anatomically based map obtained with Otoplan®, a tablet-based software that allows the cochlear duct length to be calculated starting from CT images. Methods Ten postlingually deafened patients who underwent cochlear implantation with MED-EL company devices from 2015 to 2019 in the Tertiary referral center University Hospital of Verona have been included in a retrospective study. The postoperative CT scans were evaluated with Otoplan®; the position of the intracochlear electrodes was obtained, an anatomical mapping was carried out and then it was submitted to the patients. All patients underwent pure tonal and speech audiometry before and after the reallocation and the audiological results were processed considering the Speech Recognition Threshold (SRT), the Speech Awareness Threshold (SAT) and the Pure Tone Average (PTA). The differences in the PTA, SAT and SRT values before and after the reallocation were determined. The results were statistically processed using the software Stata with a significance value of α < 0.05. Results The mean values of SRT (61.25 dB versus 51.25 dB) and SAT (49 dB versus 41 dB) were significantly lower (p: 0.02 and p: 0.04, respectively) after the reallocation. No significant difference was found between PTA values (41.5 dB versus 39.25 dB; p: 0.18). Conclusions Our preliminary results demonstrate better speech discrimination and rapid adaptation in implanted postlingually deaf patients after anatomic mapping and subsequent frequency reallocation.

Imaging-based frequency mapping for cochlear implants – Evaluated using a daily randomized controlled trial

“…Both experimental maps performed worse than the clinical map. Recently, a pilot study was published which evaluated a software-based anatomy based fitting procedure in subjects with a CI from MED-EL ( Di Maro et al, 2022 ). Here, based on post-operative CT scans, mismatch was minimized within the 950–3,500 Hz region while mismatch at low and high frequencies was tolerated.…”

“…Speech recognition deteriorated with the experimental settings, despite a 3 month habituation period. Recently, a pilot study was performed in which implanted subjects showed better results on speech discrimination tests with an anatomically based FAT compared to their routine clinical settings ( Di Maro et al, 2022 ). Other strategies to improve CI frequency distributions have also been evaluated, such as evolutionary algorithms and smartphone applications which enable FAT self-adjustment by patients ( Fu et al, 2002 ; Jethanamest et al, 2017 ; Saadoun et al, 2022 ).…”

Advancing Cochlear Implant Programming: X-ray Guided Anatomy-Based Fitting

“…Anatomy-based fitting (ABF) is a technique that allows the specific frequency of neural elements to be matched to the frequency assigned to each contact. This can reduce the adaptation time and enhance speech perception and discrimination (12). To perform a proper ABF, it is necessary to identify the position of the inserted electrode and accurately measure the angular insertion depth (AID) of the electrodes (12).…”

One Click Is Not Enough: Anatomy-Based Fitting in Experienced Cochlear Implant Users

“…This approach is called anatomy-based fitting (ABF) with the aim to reduce the frequency to place mismatch. To our knowledge, only one investigation has attempted to apply ABF using the aforementioned clinical fitting software (7), without further modifications from the manufacturer. However, based on the before experience from our clinic, we found the "as is" application of ABF as implemented by the manufacturer unsuccessful because the lowest frequency band is too large; hence, patients did not accept the sound quality.…”