# Project 3: Efficiency of Language Processing

> **NIH NIH P50** · UNIVERSITY OF IOWA · 2024 · $349,173

## Abstract

PROJECT 3: PROJECT SUMMARY
In work on hearing loss, variability in outcomes is a persistent puzzle. Listeners with comparable hearing do
not always perform similarly in noise or the real world. Project 3 proposes this derives from two linked issues.
First, clinical tests focus on accuracy. But accuracy is not sufficient. To cope with real-world demands, speech
perception must be efficient and flexible. Second, not all variation is due to the auditory periphery. Cognitive
ability, which declines with age, could exacerbate the effects of hearing loss. However, research has largely
focused on general cognitive skills like working memory. Mechanisms specific to language have not received
much attention. Project 3 links these issues, testing the hypothesis that the cognitive mechanisms of language
processing are how listeners achieve efficiency and flexibility. We address this in word recognition, a hub in the
language system linking sound and meaning. Cognitive models suggest listeners match the speech signal to
thousands of candidates in the lexicon via a competition process, and that variation in efficiency and flexibility
are emergent from this competition. This is tested with eye-movements techniques that yield a temporally rich
picture of the dynamics of competition. Prior work suggests two profiles of competition for CI users. Successful
CI users show a small delay and keep competitors available to facilitate revisions after a mistake. In contrast,
listeners who struggle wait to access candidates until most of the word is heard and show reduced competition.
Project 3 asks if these dimensions of efficiency are uniquely important for outcomes over and above the
auditory periphery. Data from the last funding cycle support this idea, linking efficiency to aging, listening effort,
the listening environment, and cortical structure. Project 3 builds on this with four aims. Aim 1 conducts a large
multi-modal cross-sectional study of experienced CI users and a longitudinal study of new recipients. These
studies ask what factors drive differences in efficiency, both in the moment and during adaptation to the CI.
They investigate the role of real-world practice (using ecological momentary assessment, social network
analysis and device logs), language skills (using neuropsychological tests and a new reading/eye-movement
task), cortical integrity (using pre-implantation MRI), and listening effort (using pupillometry). They also ask
whether differences in efficiency predict differences in outcomes including the ability to keep up with fast
speech. Aim 2 asks how the dimensions of efficiency adapt to challenging listening, using a novel experimental
paradigm in which sentence contexts create expectations for either noise or rapid speech. Aim 3 asks whether
efficiency is related to the way CI users combine information across ears. It uses a dichotic listening paradigm
to ascertain whether information is combined into a composite object prior to speech recognit...

## Key facts

- **NIH application ID:** 10841419
- **Project number:** 5P50DC000242-37
- **Recipient organization:** UNIVERSITY OF IOWA
- **Principal Investigator:** Bob McMurray
- **Activity code:** P50 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $349,173
- **Award type:** 5
- **Project period:** 1985-09-15 → 2028-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10841419

## Citation

> US National Institutes of Health, RePORTER application 10841419, Project 3: Efficiency of Language Processing (5P50DC000242-37). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10841419. Licensed CC0.

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