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.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
460
* Recall of meaningful sentences, anomalous word strings, and unstructured word lists * Measurement of syntactic and semantic gain * Pupillometry during auditory and visual presentation
* Two-choice word recognition task with semantic priming/luring in multi-talker babble * Three Signal-to-Noise Ratio (SNR) levels (heavy, medium, light noise) * Confidence ratings for responses * Pupillometry measurement
* Speech recognition and recall of single sentences vs. paired sentences * Manipulation of inter-sentence semantic predictability (high vs. low) * Four test conditions: 1-sentence, 2-sentences, 2-sentences+pre-prompt, 2-sentences+post-prompt * Pupillometry during task
* Recall of 27 narrative passages (67-97 words each) * Propositional analysis scoring (main ideas, mid-level ideas, details) * Measurement of semantic hierarchy effect * Pupillometry during listening
* 24 discourse passages (150 words each): 12 narrative, 12 expository * Continuous presentation vs. self-paced presentation (stops at clause/sentence boundaries) * Measurement of pause times and comprehension recall * Pupillometry during task
* Self-Paced Sentence Comprehension * Sentences with varying syntactic complexity (active-conjoined, subject-relative, object-relative) * Continuous vs. self-paced (with pause at major clause boundary) presentation * True/false comprehension verification statements * Pupillometry measurement
Brandeis University
Waltham, Massachusetts, United States
RECRUITINGNYU Langone Health
New York, New York, United States
RECRUITINGPercent correct Consonant-Nucleus-Consonant (CNC) words across experiments 1-3
Participants' ability to recognize individual spoken words will be assessed using the Consonant-Nucleus-Consonant (CNC) word test. Outcome is based on the percent of key words correctly repeated. Higher score indicate better speech understanding.
Time frame: End experiments 1-3 (up to 9 hours)
Percent correct AzBio sentences across experiments 1-3
The AzBio sentence test consists of 15 lists of 20 sentences each. AzBio sentences are spoken by different talkers in a conversational style with limited contextual cues that the listener can use to predict or 'fill in' unintelligible words. Outcome is based on the percent of AzBio sentences correctly repeated. Higher score indicate better speech understanding.
Time frame: End experiments 1-3 (up to 9 hours)
Error rates for word identification tasks across experiments 1-3
Time frame: End experiments 1-3 (up to 9 hours)
Percentage of propositions recalled from narrative passages
Subjects will hear 24 150- word passages, with one half of the passages being narrative (tell a story with a setting, theme, plot, etc.) and the other half being expository (e.g. instructions from a health care provider). After each passage the subject will be asked to recall as much of the passage content as possible. Higher score indicate better speech understanding.
Time frame: End of experiment 4 (up to 3 hours)
Ratio of main idea recall to detail recall
Subjects will hear recorded narratives and will be asked to recall them as best as they can. The narratives will include main ideas (defined as propositions whose arguments are directly related to the overall meaning of the passage), mid-level propositions (those that take main propositions as their arguments), and details (propositions that take mid-level or other minor propositions as their arguments. Ratio of main idea recall to detail recall will be assessed.
Time frame: End of experiment 4 (up to 3 hours)
Percentage of true/false statements identified
Subjects will hear sentences with syntactic forms known to be graded in comprehension difficulty: active-conjoined sentences (The author insulted the critic // and the critic hired a lawyer), subject-relative sentences (The author that insulted the critic // hired a lawyer), and object-relative sentences (The author that the critic insulted // hired a lawyer). The subject will hear an equal number of each sentence type, where half are presented with self-pacing, and half are presented without interruption. After each sentence the subject will be presented that they must indicate is true or false about the sentence they just heard.
Time frame: End of experiment 6 (up to 3 hours)
Percent correct increase from unstructured word lists to anomalous sentences (syntactic gain)
Participants will hear 30 meaningful, eight-word sentences to begin. The words from this list of sentences will then be used to create the unstructured word lists and syntactic strings, such that each word would be heard equally as often across the three stimulus conditions. Therefore, each subject will hear a total of 30 meaningful sentences, 30 anomalous strings, and 30 unstructured lists, presented in a counter-balanced design. Recall accuracy for the three conditions will be compared.
Time frame: End of experiment 1 (up to 3 hours)
Percent correct increase from anomalous sentences to meaningful sentences (semantic gain).
Participants will hear 30 meaningful, eight-word sentences to begin. The words from this list of sentences will then be used to create the unstructured word lists and syntactic strings, such that each word would be heard equally as often across the three stimulus conditions. Therefore, each subject will hear a total of 30 meaningful sentences, 30 anomalous strings, and 30 unstructured lists, presented in a counter-balanced design. Recall accuracy for the three conditions will be compared.
Time frame: End of experiment 1 (up to 3 hours)
Number semantically-driven misrecognitions in lure conditions
Subjects will hear word pairs, with the second (target) word of the pair presented in multi-talker babble. There will be three conditions: Neutral prime (the first word is unrelated to the target word, e.g. Jaw-PASS), Semantic prime (the two words are semantic associates, e.g. Row - BOAT), and Semantic lure (the target word is a semantic associate of a similar word e.g. Row - GOAT, where GOAT is a lure for BOAT), thus putting the semantic context in conflict with successful perception. Number semantically-driven misrecognitions in lure conditions will be assessed.
Time frame: End of experiment 2 (up to 3 hours)
Frequency of semantically-driven misrecognitions in lure conditions
Subjects will hear word pairs, with the second (target) word of the pair presented in multi-talker babble. There will be three conditions: Neutral prime (the first word is unrelated to the target word, e.g. Jaw-PASS), Semantic prime (the two words are semantic associates, e.g. Row - BOAT), and Semantic lure (the target word is a semantic associate of a similar word e.g. Row - GOAT, where GOAT is a lure for BOAT), thus putting the semantic context in conflict with successful perception. Frequency of semantically-driven misrecognitions in lure conditions will be assessed.
Time frame: End of experiment 2 (up to 3 hours)
Difference in recall accuracy between single-sentence and two-sentence conditions
Subjects will undergo four test conditions (two will require remembering only one sentence and the other two will require remembering two sentences). For each condition there will be two combinations of semantic association between the first and second sentence (half will have high predictability, and the other half will have low predictability). Difference in recall accuracy between single-sentence and two-sentence conditions will be assessed.
Time frame: End of experiment 3 (up to 3 hours)
Difference in comprehension improvement (percentage of proposition's correctly recalled) with self-paced vs. continuous presentation
Subjects will hear 24 150- word passages, with one half of the passages being narrative (tell a story with a setting, theme, plot, etc.) and the other half being expository (e.g. instructions from a health care provider). After each passage the subject will be asked to recall as much of the passage content as possible. Subjects will be presented with equal numbers of "self-paced" passages (stopping at major clauses and sentence boundaries, subject decides when to continue) and passages presented without interruption.
Time frame: End of experiment 5 (up to 3 hours)
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