# Interactive Effects of Aging and Blast Exposure on Central Auditory System

> **NIH VA IK2** · VA LOMA LINDA HEALTHCARE SYSTEM · 2020 · —

## Abstract

Many blast-exposed Veterans report difficulty in complex listening situations (e.g., understanding speech in
noise) despite normal or near-normal performance on standard audiological tests. This suggests a deficit in
central auditory processing. Indeed, blast-exposed Veterans perform abnormally on central auditory tests,
particularly those assessing temporal processing. A similar pattern is observed in middle age adults who often
have good peripheral hearing but show deficits on tests of temporal processing and speech understanding in
noise. Age-related auditory deficits have been linked to functional and anatomical changes in the central
auditory system. The physiologic origin of auditory deficits in blast-exposure is currently unknown, although the
similarity in behavioral profiles between aging and blast exposure suggests similar mechanisms may be
affected. It is therefore possible that the auditory deficits experienced by blast-exposed Veterans will intensify
as they enter middle age and beyond. This has not been investigated systematically. The present study will
determine: (a) whether there is an interaction between aging and blast exposure on temporal processing and
speech recognition (Specific Aim 1); (b) whether age- and/or blast-related differences in behavioral
performance can be linked to neuroanatomical changes within or outside the auditory system (Specific Aim
2); and (c) whether aging, blast exposure, or their interaction lead to changes in functional representations of
speech in the auditory cortex (Specific Aim 3). Groups of 50 blast-exposed and 50 unexposed Veterans will
be tested. Young (18-39 years) and middle age (40-60 years) Veterans will be represented in equal numbers
within each blast exposure group. Each participant will be assessed on a number of temporal processing and
speech recognition tests known to reveal deficits in middle age listeners. Gray and white matter morphology
will be assessed using T1- and diffusion-weighted magnetic resonance imaging (MRI). Finally, cortical activity
will be measured during a competing speech task using functional MRI. We hypothesize that aging and blast
exposure will produce interactive effects on performance in temporal processing and speech tests, and that
performance will be linked to changes in the structural and functional integrity of the central auditory nervous
system. We will test for alternatives, e.g., that auditory performance is linked to cognitive ability or brain health
outside the auditory system. We expect our findings will: (a) lead to improvements in diagnosis and
classification of central auditory deficits; and (b) motivate focused rehabilitation strategies. This study will build
on the candidate’s previous research using psychophysical and neuroimaging techniques to examine speech
processing in listeners with normal hearing and sensorineural hearing loss. A strong mentorship team will
contribute to research and career development. Dr. Marjorie Leek is the primar...

## Key facts

- **NIH application ID:** 9878679
- **Project number:** 5IK2RX002702-03
- **Recipient organization:** VA LOMA LINDA HEALTHCARE SYSTEM
- **Principal Investigator:** Jonathan Henry Venezia
- **Activity code:** IK2 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2020
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2018-01-01 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9878679

## Citation

> US National Institutes of Health, RePORTER application 9878679, Interactive Effects of Aging and Blast Exposure on Central Auditory System (5IK2RX002702-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9878679. Licensed CC0.

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