Measuring listening effort expended by adolescents and young adults with unilateral or bilateral cochlear implants or normal hearing

Abstract

Objectives

To compare the listening effort expended by adolescents and young adults using implants versus their peers with normal hearing when these two groups are achieving similar speech perception scores. The study also aimed to compare listening effort expended by adolescents and young adults with bilateral cochlear implants when using two implants versus one.

Methods

Eight participants with bilateral cochlear implants and eight with normal hearing aged 10–22 years were included. Using a dual-task paradigm, participants repeated consonant–nucleus–consonant (CNC) words presented in noise and performed a visual matching task. Signal-to-noise ratios were set individually to ensure the word perception task was challenging but manageable for all. Reduced performance on the visual task in the dual-task condition relative to the single-task condition was indicative of the effort expended on the listening task.

Results

The cochlear implant group, when using bilateral implants, expended similar levels of listening effort to the normal hearing group when the two groups were achieving similar speech perception scores. For three individuals with cochlear implants, and the group, listening effort was significantly reduced with bilateral compared to unilateral implants.

Discussion

The similar amount of listening effort expended by the two groups indicated that a higher signal-to-noise ratio overcame limitations in the auditory information received or processed by the participants with implants. This study is the first to objectively compare listening effort using two versus one cochlear implant. The results provide objective evidence that reduced listening effort is a benefit that some individuals gain from bilateral cochlear implants.

Keywords:

• Hearing impairment
• Cochlear implant
• Bilateral cochlear implants
• Listening effort
• Adolescents
• Children
• Dual-task paradigm

Acknowledgements

The authors are grateful to the young adults and to the adolescents and their parents who participated in this research. Thank you also to Neven Tomov, who developed the software used in the testing procedure and to Colleen Holt for her comments and help with editing early versions of the manuscript. Ethical approval for this work was given by the Human Research Ethics Committee of the Royal Victorian Eye and Ear Hospital, Melbourne (Project No. 02/506H/07).