NCT07765186

Brief Summary

Understanding speech in restaurants and other noisy environments is the most common complaint from the more than 60 million Americans with hearing impairment. Succeeding in such environments requires a listener to first segregate sound sources and then selectively attend to the source of interest. This study examines how individual auditory spatial cues (interaural time differences and interaural level differences) support spatial selective attention, the cortical processes that underlie this ability, and how these processes are modulated by task demands. Participants with normal hearing and participants who use bilateral cochlear implants will perform listening tasks while brain and physiological responses are recorded (electroencephalography, functional near-infrared spectroscopy, pupillometry, and, for normal-hearing participants only, functional magnetic resonance imaging). The findings will provide new insights into the mechanisms of spatial selective attention and help guide clinical solutions for cochlear implant users, individuals with hearing impairment more generally, and older normal-hearing adults who have difficulty understanding speech in noisy environments.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
80

participants targeted

Target at P50-P75 for not_applicable

Timeline
47mo left

Started Oct 2025

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress17%
Oct 2025Jul 2030

Study Start

First participant enrolled

October 22, 2025

Completed
10 months until next milestone

First Submitted

Initial submission to the registry

August 10, 2026

Completed
4 days until next milestone

First Posted

Study publicly available on registry

August 14, 2026

Completed
3.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

April 1, 2030

Expected
3 months until next milestone

Study Completion

Last participant's last visit for all outcomes

July 1, 2030

Last Updated

August 14, 2026

Status Verified

August 1, 2026

Enrollment Period

4.4 years

First QC Date

August 10, 2026

Last Update Submit

August 10, 2026

Conditions

Keywords

spatial hearingauditory selective attentioninteraural level differenceinteraural time differencecochlear implantEEGfNIRSfMRIpupillometryspeech in noise

Outcome Measures

Primary Outcomes (5)

  • EEG

    EEG data acquired using 32 Ag-Ag/Cl electrodes embedded in an elastic cap (Brain Products), impedances below 20 kOhms, locations per the extended 10-20 system, recorded at 5 kHz from 0.1-100 Hz. Event-related potentials (including attentional modulation of the N1) and parietal alpha lateralization are compared across spatial-cue and task-demand conditions.

    2 hours

  • NIRS

    Functional near-infrared spectroscopy collected with a montage targeting bilateral superior temporal gyrus (STG) and bilateral prefrontal cortex, using a NIRSport 2 8x8 channel system (NIRx) with long- and short-distance channel probes; 3D structural head scanning registers probe placement. Optical signals recorded at 10 Hz with an average source-detector distance of 35 mm. Oxygenated and deoxygenated hemoglobin responses are compared across conditions.

    2 hours

  • Pupillometry

    Pupil dilation from both eyes recorded with the EyeLink 1000 at a sampling rate of 1000 Hz, normalized to each participant pupillary dynamic range, as an index of listening effort across conditions.

    2 hours

  • MRI

    Data acquired on a 3 Tesla Siemens Prisma MRI scanner (64-channel head coil). High-resolution (0.8 mm iso) T1-weighted multi-echo MP-RAGE and T2-weighted SPACE images collected for cortical reconstruction (FreeSurfer); functional MRI measures stimulus-induced lateralization and spatial receptive fields in auditory cortex. Normal-hearing arm only.

    2 hours

  • Discrimination (DISCR)

    Behavioral discrimination performance for spatialized sounds. HRTFs span +/- 90 degrees, broadband ILDs span +/- 20 dB, and broadband ITDs span +/- 800 microseconds; values chosen to roughly equate perceived lateral range across cues.

    2 hours

Study Arms (2)

Bilateral Cochlear Implant Users

OTHER

Adults with existing bilateral cochlear implants (implanted and using their devices for at least one year). Participants complete the discrimination and selective-attention auditory paradigms with manipulated spatial cues while combined EEG, fNIRS, and pupillometry are recorded. No fMRI is collected in this arm due to device safety concerns.

Device: Existing bilateral cochlear implants

Normal Hearing Controls

OTHER

Adults with audiometrically confirmed normal hearing (thresholds within 20 dB HL of normal through 8 kHz). Participants complete three auditory attention paradigms (working memory, discrimination, selective attention) with manipulated spatial cues, under combined EEG, fNIRS, and pupillometry sessions and fMRI sessions.

Other: Normal Hearing Control

Interventions

Participants in this arm are recruited from a population who have existing bilateral cochlear implants. The implants are the participants' own clinical devices, used as clinically programmed; no investigational device or modification is provided by the study. Auditory attention tasks are presented with manipulated spatial cues (interaural time differences, interaural level differences, or HRTFs).

Bilateral Cochlear Implant Users

Control group recruited from the normal hearing population. Participants perform the same auditory attention tasks with manipulated spatial cues (interaural time differences, interaural level differences, or HRTFs) under EEG/fNIRS/pupillometry and fMRI.

Normal Hearing Controls

Eligibility Criteria

Age18 Years - 90 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Adults with normal hearing, confirmed by audiometric assessment (thresholds within 20 dB HL of normal through 8 kHz), OR adults with bilateral cochlear implants who have used their implants for at least one year
  • Native speakers of American English
  • Normal or corrected-to-normal vision

You may not qualify if:

  • Known neurological disorders
  • For fMRI sessions (normal-hearing participants only): contraindications to MRI scanning; cochlear implant users do not complete MRI sessions

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of South Florida, PCD Building, Room 3008A

Tampa, Florida, 33620, United States

RECRUITING

MeSH Terms

Conditions

Hearing Loss, Bilateral

Condition Hierarchy (Ancestors)

Hearing LossHearing DisordersEar DiseasesOtorhinolaryngologic DiseasesSensation DisordersNeurologic ManifestationsNervous System DiseasesSigns and SymptomsPathological Conditions, Signs and Symptoms

Study Officials

  • Christopher A Brown, PhD

    University of South Florida

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Christopher A Brown, PhD

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Model Details: Case-control-style design with two participant populations (normal-hearing adults and adult bilateral cochlear implant users). All experimental manipulations (spatial cue type, task demands) are within-subject.
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Associate Professor

Study Record Dates

First Submitted

August 10, 2026

First Posted

August 14, 2026

Study Start

October 22, 2025

Primary Completion (Estimated)

April 1, 2030

Study Completion (Estimated)

July 1, 2030

Last Updated

August 14, 2026

Record last verified: 2026-08

Data Sharing

IPD Sharing
Will share

De-identified individual participant data for all primary measures (behavioral, EEG, fNIRS, pupillometry, and MRI) will be publicly shared in BIDS-compliant format, per the NIH Data Management and Sharing Plan for this award. Smaller datasets (demographics, behavioral scores) will be shared as text/CSV files via GitHub and permanently archived on Zenodo; larger neuroimaging datasets will be shared on Zenodo directly, with permanent DOIs. Custom acquisition and analysis software will also be shared via GitHub and archived on Zenodo.

Shared Documents
ANALYTIC CODE
Time Frame
Data supporting each publication will be shared no later than the time of publication, and retained permanently (Zenodo provides permanent archiving with DOIs).
Access Criteria
Publicly available with no access restrictions.

Locations