# Benefits of speech-based audiometry and low-gain hearing aids for blast-exposed Veterans

> **NIH VA I01** · VA LOMA LINDA HEALTHCARE SYSTEM · 2024 · —

## Abstract

Many blast-exposed Veterans have trouble in challenging listening situations (e.g., understanding speech in
background noise) despite normal or near-normal peripheral hearing as measured by the pure-tone audiogram,
which we refer to as “functional hearing difficulty” (FHD). Until recently, it was unclear whether FHDs can arise
from direct trauma to the central auditory system. Preliminary studies from the PI’s Career Development Award-
2 show that blast exposure: (i) damages auditory-cortical white matter tracts resulting in poorer scores on
speech-in-noise tests; and (ii) produces a shift in the cortical response to speech such that background
interference leads to more activation in brain regions associated with effortful listening. These findings strongly
suggest a central contribution to blast related FHDs. In the past decade, VA audiologists have increasingly used
low-gain hearing aids to treat FHDs, but this is problematic because conventional hearing aid fitting relies mostly
on the audiogram. Thus, conventional approaches require clinical intuition to adapt the treatment to the unique
needs of Veterans with FHDs. This problem also applies to sensorineural hearing loss, which has consequences
beyond the peripheral structures assessed by the audiogram. This study proposes a novel data-driven approach
to hearing aid fitting called speech-based audiometry (SBA). Briefly, SBA uses “Learning Machines” to structure
patient-audiologist interactions toward selection of an optimal hearing-aid gain profile based on the patient’s
subjective responses to aided speech. By efficiently searching a space of possible gain profiles for the optimum
solution, SBA combines assessment, gain prescription, and fit refinement in a single procedure, without
appealing to the audiogram. Sixty blast-exposed Veterans with FHDs will be recruited into an early-stage clinical
trial and fitted for low-gain hearing aids using either the conventional approach or SBA (N = 30 per group). They
will be followed for six weeks, with each group further divided into subgroups (N = 15) assigned to use their
hearing aids daily or only during laboratory assessments. In Specific Aim 1, aided listening benefit will be
assessed at the beginning and end of the study period using a traditional speech-in-noise instrument, the
modified Quick Speech-in-Noise test. To track the effects of acclimatization to aided listening, participants will
also complete a modified Digits in Noise (DIN) test once per week. Performance on the DIN will be measured
traditionally (threshold signal-to-noise ratio) and in terms of “intraindividual variability,” which is inferred from
response times at higher signal-to-noise ratios and reflects cognitive effort. In Specific Aim 2, participants will
complete a speech-in-noise fMRI task at the beginning and end of the study period. The task will be completed
with and without amplification using a simulated hearing aid to match each participant’s true gain prescription....

## Key facts

- **NIH application ID:** 10866281
- **Project number:** 1I01RX005059-01
- **Recipient organization:** VA LOMA LINDA HEALTHCARE SYSTEM
- **Principal Investigator:** Jonathan Henry Venezia
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2024
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2024-04-01 → 2028-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10866281

## Citation

> US National Institutes of Health, RePORTER application 10866281, Benefits of speech-based audiometry and low-gain hearing aids for blast-exposed Veterans (1I01RX005059-01). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10866281. Licensed CC0.

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