Background: Clinical tests for the assessment of spatial listening require multi-speaker arrays rarely available in clinical settings. A virtual-audio version of the Spatial Speech in Noise Test (SSiN; Bizley et al., 2015) leads to similar performance across spatial locations for loudspeaker arrays with normal-hearing listeners (Salorio-Corbetto et al., 2022). The aim of this work is to determine whether the virtual-audio versions of the SSiN and the Adaptive Sentence List (ASL; (MacLeod & Summerfield, 1990) using a spatial release from masking test configuration test yield comparable results than their loudspeaker versions for children with bilateral cochlear implants. Additionally, the efficacy of a centralisation app to identify the degree of balance between the ears was explored together with the findings from the virtual speech tests. The purpose of this work is to validate virtual assessments for use in a clinical trial with virtual reality spatial training games.

Method: A participatory-design approach was used to develop and finalise the virtual-audio implementations of the tests (Vickers et al., 2021). Ten children and young adults who wear bilateral cochlear implants and ten age-matched normal-hearing participants, will perform each test (SSiN and Spatial ASLs) in each implementation (virtual-audio or loudspeaker). The order of the tests and implementations were counterbalanced across participants. The participants also completed the centralisation task (i-balance app) using narrow-band noise and wide-band stimuli consisting of speech-shaped noise and a non-language specific speech-like stimulus (Holube et al., 2010). The interaural level differences for these stimuli were varied by the children using a visual/tactile interface so that the sound was perceived in the midline. Children were asked to show where they located or heard the sound relative to their head by colouring a drawing.

Results: So far, the virtual-audio applications were finalised. Eight participants with cochlear implants and six with normal hearing have completed the tests. Our outcomes will allow us to determine whether the virtual-audio versions of the tests have potential for clinical use, provide the validation for use in the clinical trial and determine whether the results from the centralisation task used in the i-balance app are informative in terms of spatial hearing abilities for children with bilateral cochlear implants.

References:

• Bizley, J.K., Elliott, N., Wood, K.C., Vickers, D.A., 2015. Simultaneous assessment of speech identification and spatial discrimination: A potential testing approach for bilateral cochlear implant users? Trends in Hearing, 19, p.2331216515619573. doi:10.1177/2331216515619573.
• Holube, I., Fredelake, S., Vlaming, M., Kollmeier, B., 2010. Development and analysis of an International Speech Test Signal (ISTS). International Journal of Audiology, 49(12), p.891–903. doi:10.3109/14992027.2010.506889.
• MacLeod, A., Summerfield, Q., 1990. A procedure for measuring auditory and audio-visual speech-reception thresholds for sentences in noise: rationale, evaluation, and recommendations for use. British Journal of Audiology, 24, p.29–43.
• Salorio-Corbetto, M., Williges, B., Lamping, W., Picinali, L., Vickers, D.A., 2022. Evaluating Spatial Hearing using a Dual-Task Approach in a Virtual Acoustics Environment. Frontiers in Neuroscience, p.46.
• Vickers, D.A., Salorio-Corbetto, M., Driver, S., Rocca, C., Levtov, Y., et al, 2021. Involving children and teenagers with bilateral cochlear implants in the design of the BEARS (Both EARS) virtual reality training suite improves personalization of the intervention. Frontiers in Digital Health, p.156.