Improving Spatial Perception and Speech Understanding in Multitalker Mixtures

The purpose of this study is to investigate several approaches for improving spatial perception and speech intelligibility in multitalker listening situations for hearing-aid users. The hypotheses are that spatial perception and speech intelligibility will be improved by (1) increased high-frequency audibility, (2) speech envelope enhancement, and/or (3) appropriate sound image externalization.

Study Overview

• Status: Recruiting
• Conditions: Hearing Loss
• Intervention / Treatment: Other: hearing aid condition

Detailed Description

The purpose of this study is to investigate several approaches for improving spatial perception and speech intelligibility in multitalker listening situations for hearing-aid users. Aim 1 will investigate how well different amplification strategies provide access to the spectrotemporally sparse speech information that is available in multitalker mixtures. The hypothesis is that subtle differences in high-frequency audibility across different strategies may have much greater effects on the intelligibility of sparse speech than intact speech. This Aim will involve 40 subjects with hearing loss across 2 experiments. Aim 2 is an exploratory aim that will investigate the potential of a speech enhancement algorithm to improve spatial hearing in multitalker mixtures. The hypothesis is that speech enhancement, in addition to its established monaural benefits, will enhance the salience of interaural time differences and thus provide binaural benefits in multitalker mixtures. This Aim will involve 30 subjects with normal hearing and 60 subjects with hearing loss across 3 experiments. Aim 3 will investigate how different hearing-aid styles affect sound externalization. The hypothesis is that hearing aids can disrupt sound externalization, which in turn impacts speech intelligibility in multitalker mixtures. This Aim will involve 30 subjects with normal hearing and 60 subjects with hearing loss across 3 experiments.

This is a prospective design involving adult human subjects. While the investigators will recruit subjects with normal and impaired hearing, all subjects will be assigned to the same set of experimental conditions. Therefore, for the purposes of intervention (or prospective assignment), the subjects can be treated as a single group completing the same intervention (or set of interventions). The behavioral experiments involve listening to speech sounds (either unaided, with hearing aids, or with simulated hearing aids), and providing responses related to spatial perception or speech intelligibility. The order of experimental conditions will be randomized for each subject in order to control for order effects. All of the experimental tasks and outcome measures have been previously established, have good reliability and validity, and will be appropriate for informing future studies.

• Study Type: Interventional
• Enrollment (Estimated): 220
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Virginia A Best, PhD; Phone Number: (617) 353-2622; Email: ginbest@bu.edu
• Study Contact Backup: Name: Christine Mason; Phone Number: cmason@bu.edu; Email: cmason@bu.edu

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Recruiting
      • Boston University
      • Contact: Virginia Best; Phone Number: 617-353-2622; Email: ginbest@bu.edu
      • Principal Investigator: Virginia A Best, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria: Normal-Hearing Subjects

• 18 to 35 years of age
• Audiometric thresholds that do not exceed 20 dB HL at any frequency from 250 to 8000 Hz
• Able to provide informed consent and understand experimental instructions
• Normal or corrected-to-normal vision

Inclusion Criteria: Hearing-Impaired Subjects

• 18 to 80 years of age
• Documented sensorineural hearing loss
• Able to provide informed consent and understand experimental instructions
• Normal or corrected-to-normal vision

Exclusion Criteria (some experiments)

• Non-native speakers of English

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Experimental condition; Participants will be presented with sound stimuli under a number of experimental conditions that simulate different hearing-aid conditions.	Other: hearing aid condition; The intervention will be a hearing aid or a modification to the sound stimulus that simulates a hearing aid configuration, style, or processing strategy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Speech intelligibility at baseline	Speech intelligibility scores will be measured in a baseline condition (e.g. unaided) and in a number of hearing-aid conditions (post-intervention). Scale is in percent correct (0-100%).	Baseline
Speech intelligibility post-intervention	Speech intelligibility scores will be measured in a baseline condition (e.g. unaided) and in a number of hearing-aid conditions (post-intervention). Scale is in percent correct (0-100%).	Up to 4 hours
Speech reception threshold at baseline	Speech reception thresholds will be measured in a baseline condition (e.g. unaided) and in a number of hearing-aid conditions (post-intervention). Scale is in decibels (the level of the target speech relative to the masker speech needed to identify 50% of the words in a sentence).	Baseline
Speech reception threshold post-intervention	Speech reception thresholds will be measured in a baseline condition (e.g. unaided) and in a number of hearing-aid conditions (post-intervention). Scale is in decibels (the level of the target speech relative to the masker speech needed to identify 50% of the words in a sentence).	Up to 4 hours
Interaural time difference discrimination at baseline	Thresholds for the discrimination of interaural time differences in speech will be measured in a baseline condition (e.g. unaided) and in a number of hearing-aid conditions (post-intervention). Scale is in microseconds.	Baseline
Interaural time difference discrimination post-intervention	Thresholds for the discrimination of interaural time differences in speech will be measured in a baseline condition (e.g. unaided) and in a number of hearing-aid conditions (post-intervention). Scale is in microseconds.	Up to 4 hours
Externalization rating at baseline	Externalization judgments for speech will be measured in a baseline condition (e.g. unaided) and in a number of different hearing-aid conditions (post-intervention). Scale is in percent (0-100%).	Baseline
Externalization rating post-intervention	Externalization judgments for speech will be measured in a baseline condition (e.g. unaided) and in a number of different hearing-aid conditions (post-intervention). Scale is in percent (0-100%).	Up to 4 hours

Collaborators and Investigators

• Sponsor: Boston University Charles River Campus
• Collaborators: National Institute on Deafness and Other Communication Disorders (NIDCD)
• Investigators: Principal Investigator: Virginia A Best, PhD, Boston University

Study record dates

Study Major Dates

• Study Start (Actual): March 9, 2022
• Primary Completion (Estimated): November 30, 2026
• Study Completion (Estimated): November 30, 2026

Study Registration Dates

• First Submitted: February 4, 2022
• First Submitted That Met QC Criteria: February 17, 2022
• First Posted (Actual): March 2, 2022

Study Record Updates

• Last Update Posted (Estimated): September 24, 2025
• Last Update Submitted That Met QC Criteria: September 19, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Hearing Aids; Speech Intelligibility; Spatial Hearing; Cocktail Party; Audibility; Sound Image Externalization; Speech Envelope
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Otorhinolaryngologic Diseases; Sensation Disorders; Ear Diseases; Hearing Disorders; Pathological Conditions, Signs and Symptoms; Behavior; Signs and Symptoms; Communication; Verbal Behavior; Speech; Hearing Loss; Speech Intelligibility
• Other Study ID Numbers: 4218E; R01DC015760 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Individual participant data that underlie results in a publication will be made publicly available.
• IPD Sharing Time Frame: The data will be made available at the time of the relevant publication.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No