# Do Different Types of Microphones Affect Listening Effort in Cochlear Implant Recipients? A Pupillometry Study

## TL;DR

This study investigates how different microphones affect listening effort in cochlear implant users using pupillometry.

## Contribution

The study introduces a pupillometry-based assessment of listening effort in cochlear implant recipients with different microphone types.

## Key findings

- Adaptive directional microphones showed varying effects on noise reduction and listening effort.
- Opti Omni microphone resulted in higher noise levels compared to Split Dir and Speech Omni.
- Pupillometry data did not correlate significantly with microphone types or sound configurations.

## Abstract

Background: It is known that subjects with a cochlear implant (CI) need to exert more listening effort to achieve adequate speech recognition compared to normal hearing subjects. One tool for assessing listening effort is pupillometry. The aim of this study is to evaluate the effectiveness of adaptive directional microphones in reducing listening effort for CI recipients. Methods: We evaluated listening in noise and listening effort degree (by pupillometry) in eight bimodal subjects with three types of CI microphones and in three sound configurations. Results: We found a correlation only between sound configurations and listening in noise score (p-value 0.0095). The evaluation of the microphone types shows worse scores in listening in noise with Opti Omni (+3.15 dB SNR) microphone than with Split Dir (+1.89 dB SNR) and Speech Omni (+1.43 dB SNR). No correlation was found between microphones and sound configurations and within the pupillometric data. Conclusions: Different types of microphones have different effects on the listening of CI patients. The difference in the orientation of the sound source is a factor that has an impact on the listening effort results. However, the pupillometry measurements do not significantly correlate with the different microphone types.