# Subjective and Somatic Tinnitus; Using Functional Near-Infrared-Spectroscopy to Identify Objective Correlates in Auditory and Non-Auditory Cortices

> **NIH NIH R01** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2024 · $504,117

## Abstract

Abstract: Phantom sound perception (tinnitus) arises from aberrant central auditory pathways. Subjective
tinnitus is typically caused by hearing loss. Auditory cortex (AC) in tinnitus animal models exhibits increased
spontaneous neural firing and synchrony. Another subset of tinnitus exists whereby patients (80%) can
manipulate pitch, tone and/or volume of tinnitus with head and neck/jaw movements. Termed somatic or
somatosensory tinnitus (ST), this modulable form of phantom sound perception is associated with cortical &
subcortical plasticity. Somatosensory/trigeminal neural inputs to auditory brainstem and cortex likely underlie
ST etiology & maintenance. Thus, two forms of subjective tinnitus exist; 1. non-somatic tinnitus (non-ST;
hearing loss etiology) 2. somatic (somatosensory /trigeminal etiology).
Our group was the first to report equivalent objective neural correlates in human, non-ST, using non-invasive
brain imaging with functional near-infrared spectroscopy (fNIRS). In our completed R21 we successfully
validated an adapted fNIRS probe for the external auditory canal (EAC). Our unique design that was coupled
with traditional scalp fNIRS probes, passes NIR light into ventral AC to measure hemodynamic responses
(HRs), resting state functional neural connectivity (RSFC). We replicated predictable/published increases in AC
HRs during silence in non-ST participants that is suppressed with sound stimulation. These objective
correlates of non-ST in humans have not been evaluated in ST.
Knowledge gaps in both non-ST & ST include: 1. Do objective changes in AC HRs & RSFC in non-ST tinnitus
relate to tinnitus severity? 2. Does ST both at rest & during a somatic maneuver /somatosensory stimulation
yield objective changes in AC HRs and RSFC? 3. Can objective neural correlates from non-ST & ST be used
to construct predictive modeling/machine learning to distinguish these two forms of subjective tinnitus?
Our central hypothesis is that human non-ST & ST will reveal objective measurable patterns of AC
activity (HRs) & connectivity (RSFC) that is tinnitus severity specific that can be discerned with
machine learning algorithms: We will investigate HRs and RSFC in subjective (AIM 1) and somatic (AIM 2)
tinnitus variants. The data from these two AIMS will be considered with several tinnitus indices/questionnaires
to determine how objective brain responses in tinnitus potentially correlate with tinnitus severity. Data
generated from AIMS 1 and 2 will then provide the necessary information to build machine learning algorithms
that can then be used to predict HR and RSFC in human subjects going forward as a clinical and research tool.
Based on subjective severity and modulation properties, the goal of this AIM is to establish predictive neural
maps that may begin to individualize underlying properties of pathology that may be variant from participant to
participant. In the age of personalized medicine, this will be an important contribution to identify dis...

## Key facts

- **NIH application ID:** 10859739
- **Project number:** 1R01DC021746-01
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** Gregory Joseph Basura
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $504,117
- **Award type:** 1
- **Project period:** 2024-09-09 → 2029-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10859739

## Citation

> US National Institutes of Health, RePORTER application 10859739, Subjective and Somatic Tinnitus; Using Functional Near-Infrared-Spectroscopy to Identify Objective Correlates in Auditory and Non-Auditory Cortices (1R01DC021746-01). Retrieved via AI Analytics 2026-09-03 from https://api.ai-analytics.org/grant/nih/10859739. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*