Cochlear Implants and Listening Effort: the Interaction of Cognitive and Sensory Constraints

Cochlear Implants and Listening Effort: the Interaction of Cognitive and Sensory Constraints

This study examines how cochlear implant users understand and comprehend speech in realistic communication situations. Through six experiments measuring listening effort via pupillometry and discourse comprehension, we will investigate how linguistic context, cognitive demands, and processing time affect speech understanding in CI users, and in normal-hearing controls) to identify factors underlying communication resilience versus vulnerability and develop improved, ecologically valid assessment and rehabilitation strategies.

This research study examines how adults using cochlear implants (CIs) understand and comprehend speech in realistic communication situations. While current clinical tests focus on how well CI users can recognize single words and simple sentences, this study investigates whether success in recognizing speech sounds actually translates to understanding the meaning and content of longer conversations and discourse.

The study will include six interconnected experiments examining: (1) how CI users use linguistic context (both adaptively and maladaptively) to understand degraded speech; (2) how listening effort affects comprehension when faced with communicative challenges like remembering multiple sentences or narratives; (3) whether giving listeners control over the speed of speech presentation improves comprehension; and (4) a clinically-applicable version of these assessments.

Throughout the experiments, researchers will measure listening effort using pupillometry (tracking pupil dilation as an index of cognitive effort) combined with behavioral measures of speech recognition and comprehension. Comprehension will be assessed using a validated framework that distinguishes between understanding main ideas versus minor details in discourse passages.

The study will include cochlear implant users and normal-hearing adults listening to degraded speech simulations via vocoders. Participants will range in age from 18 to 80 years. A comprehensive baseline battery will assess perceptual abilities (speech recognition, spectral resolution, temporal processing) and cognitive abilities (working memory, processing speed, executive function).

OBJECTIVES:

Primary objectives are to identify mechanisms underlying successful speech comprehension in CI users and to determine factors associated with resilience versus vulnerability to communicative challenges. Secondary objectives include examining relationships between cognitive abilities, listening effort, and discourse comprehension outcomes.

OUTCOMES:

This research is expected to provide more ecologically valid assessment methods for CI users, identify which individuals may benefit from specific communication strategies (such as self-paced speech), and inform development of improved rehabilitation approaches that enhance real-world communication success rather than just word recognition ability.

Inclusion Criteria:

• Subjects will be otherwise healthy normal-hearing and cochlear implant (CI) adult listeners (between 18 and 80 years old).

Exclusion Criteria:

• Individuals below 18 years of age.
• Individuals with evidence of neurologic, vascular or psychiatric disease or dementia, and taking medications that might interfere with task performance.
• Individuals with a history of language disorders (besides those associated with hearing loss for the CI users). Individuals who are non-native speakers of American English.