# Transcranial stimulation combined with auditory training

> **NIH NIH R21** · BOSTON UNIVERSITY (CHARLES RIVER CAMPUS) · 2024 · $443,657

## Abstract

Project Summary/Abstract
The goal of this project is to investigate the potential of transcranial stimulation to enhance intelligibility in
speech mixtures in older adults struggling in these environments. Many older adults with and without
sensorineural hearing loss (SNHL) struggle with speech-on-speech (SOS) understanding, likely as a result of a
mixture of peripheral and central deficits in the auditory system. Whereas the peripheral deficits represent a
hard limit on performance, central deficits may be improved with experience and training. There are many
auditory training programs available that aim to optimize a listener’s performance in SOS environments, but the
benefits of these programs can be small and variable across listeners. Recent evidence shows that
transcranial alternating current stimulation (tACS) – a safe and non-invasive low level of current applied to the
scalp – can lead to improved speech-in-noise understanding in young normal hearing (NH) listeners and older
adults with SNHL during the course of stimulation. Furthermore, transcranial stimulation studies in other
domains show that it can enhance benefits from cognitive training in older adults, with effects persisting for
months. However, it is not known if tACS can enhance intelligibility or reduce listening effort for SOS in older
adult listeners specifically struggling with SOS understanding, or if tACS can enhance benefits from auditory
training during or beyond the course of stimulation. In this exploratory R21 proposal, older adults reporting and
demonstrating struggles in speech mixtures will be randomly assigned to Active tACS or Sham tACS groups.
All participants will be tested in the first visit on a baseline SOS recognition task, and again on a SOS task with
Active or Sham tACS. Participants will then complete two weeks of computer-based auditory training at home
(the Listening and Communication Enhancement, “LACE”, program; Sweetow and Sabes, 2006). Participants
will visit the lab twice during the LACE training period to undergo Active tACS or Sham tACS during the SOS
task. Listening effort will be assessed via pupillometry measured concurrently with the SOS task and via a
questionnaire through the LACE program. Performance on the SOS task will be re-assessed at 4 weeks
following enrollment in the study to assess retention of benefits. By comparing the in-laboratory change in SOS
performance and listening effort in the Active and Sham groups relative to baseline in the first visit, this project
aims to determine if tACS can improve speech intelligibility and/or reduce listening effort in listeners who
struggle with SOS (Aim 1). By comparing LACE performance and SOS performance and listening effort at all
subsequent visits, this project aims to determine if tACS can increase benefits obtained from an auditory
training program over the short and long term (Aim 2). Ultimately this work could significantly improve the
communication abilities of listeners with and ...

## Key facts

- **NIH application ID:** 11055097
- **Project number:** 1R21DC021763-01A1
- **Recipient organization:** BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
- **Principal Investigator:** Elin Roverud
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $443,657
- **Award type:** 1
- **Project period:** 2024-09-24 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11055097

## Citation

> US National Institutes of Health, RePORTER application 11055097, Transcranial stimulation combined with auditory training (1R21DC021763-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/11055097. Licensed CC0.

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