Testing the Speech Perception and Spatial Awareness of Children with a Cochlear Implant in a Virtual Classroom Environment

Abstract

Introduction: Speech perception in acoustically challenging environments remains challenging for children with cochlear implants. When considering the implementation of an automatic classifier system in the classroom, it becomes crucial to assess the potential advantages against possible drawbacks.
Consequently, the central question centers on assessing whether the positive impact on speech perception justifies the potential negative consequences for auditory spatial awareness. In this master’s thesis project a new test design was created to evaluate the speech perception and spatial awareness of children with cochlear implants in an ecologically valid classroom environment.

Methods: This master’s thesis project aimed to develop a test that was both ecologically valid and reproducible, focusing on the evaluation of three distinct conditions: Autosense on, Autosense off, and a remote microphone. Eligible participants for the study included children with cochlear implants aged between 5 and 18 years. The study utilized a virtual reality classroom environment, incorporating acoustical parameters of a real classroom setting into a 12-array loudspeaker setup. Assessment of frontal speech perception in noise was done with the digits-in-noise (DIN) test, while spatial awareness was assessed through the presentation of animal stimuli from various directions. Additionally, a randomly presented ice cream truck during the session served to evaluate environmental sound awareness (ESA). A pilot study was conducted on students, adults with cochlear implants and normal hearing children to validate the test method and fine-tune the levels of spatial awareness stimuli.

Results: The pilot study validated a virtual classroom setup for speech perception and spatial awareness in children with cochlear implants. Results from 14 participants, consisting of students, normal hearing and cochlear implant individuals, were included for test validation. Initial findings showed clarity in instructions, no adverse effects with virtual reality glasses, and comparable speech-in-noise scores in individuals. Spatial awareness tasks displayed a ceiling effect, leading to adjustments in stimuli levels. Psychometric curves for spatial awareness stimuli levels varied among cochlear implant individuals,
complicating the correlation between speech perception and spatial awareness. The test method proved suitable for normal hearing children, highlighting adaptability and ecological validity.

Conclusion: The results of this pilot study indicate the feasibility of the test for children with cochlear implants aged between 5 and 18 years. Regarding spatial awareness levels, it is recommended to use -5 dB and 0 dB SNR, with the goal of reducing the likelihood of floor or ceiling effects.