Speech Understanding in Noise Under Different Attentional Demands in Children With Typical Hearing and Cochlear Implants

OBJECTIVES: Complex listening environments are common in the everyday life of both adults and children and often require listeners must monitor possible speakers and switch or maintain attention as the situation requires. The aim of the present study was to investigate the effects of these attention dynamics on speech perception in adults, children with typical hearing (TH) and children with cochlear implants (CIs). DESIGN: Twenty-seven adults with TH (mean age 20.8 years), 24 children with TH (mean age 10.6 years), and 8 children with CIs (mean age 10.1 years) were tested on a speech understanding in noise task using AVATAR, a realistic audiovisual paradigm. Participants were asked to repeat the sentence as closely as possible. In one task, participants performed an adaptive speech-in-noise task to determine speech reception thresholds for sentences recorded by a male and a female speaker. In the second task, both male and female speakers could speak simultaneously in controlled conditions that required participants to either switch attention from one to another or maintain attention on the first. Eye-tracking data were collected concomitantly with both listening tasks, providing pupillometry and gaze behavior data. Participants also completed cognitive tests assessing memory, attention, processing speed, and language ability. RESULTS: Listening data showed that all groups had more difficulty switching attention from a distractor to a target than maintaining attention on a target and ignoring an incoming distractor. In the single-talker task, adults performed better than children, and children with TH performed better than children with CIs. In addition, pupillometry data showed that children with CIs exerted more listening effort in the single-talker task. Gaze data suggest that listeners fixate longer on target under more challenging conditions, but if demands on attention become too great, eye movements increase. Cognitive tests supported previous evidence that children with CIs' difficulties in speech understanding in noise are related to difficulties in sustaining attention. CONCLUSIONS: Switching attention is more challenging than sustaining attention in listening situations children face every day, including CI users. Furthermore, children with CIs appear to exert effort beyond what is captured by listening tasks and struggle with maintaining attention over longer periods than typically hearing peers, highlighting the need to consider the characteristics of learning environments of children with CIs even if hearing thresholds are in typical range.