Listening Volume Adjustment in Bone and Air Conduction Headphones

November 9, 2026 updated by: Xiao Liu, Second Affiliated Hospital, Zhejiang University, School of Medicine

Behavioral Comparison of Self-Adjusted Listening Volume in Bone Conduction Versus Air Conduction Headphones in Noise

Open-ear bone conduction headphones are increasingly used as an alternative to conventional in-ear air conduction headphones. Because bone conduction headphones do not block the ear canal, it is often assumed that users may be more affected by background noise and may increase their listening volume to hear music clearly. However, direct evidence supporting this assumption is limited.

This study aims to compare self-adjusted listening volumes between bone conduction and air conduction headphones under different background noise conditions. Approximately 32 healthy adults aged 18-35 years with normal hearing will participate in the study. Each participant will test three listening conditions: in-ear air conduction headphones, open-ear bone conduction headphones, and bone conduction headphones combined with ear occlusion. Each condition will be tested in a quiet environment and under four levels of background noise (30, 40, 50, and 60 dB(A)).

Participants will listen to the same music and adjust the volume themselves to a level they consider comfortable and clear for prolonged listening. The selected listening volume and adjustment behavior will be recorded and compared across headphone types and noise conditions.

The findings may provide behavioral evidence on whether open-ear bone conduction headphone users choose higher listening volumes in noisy environments compared with users of conventional in-ear air conduction headphones, helping to improve understanding of potential noise exposure and hearing safety.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
32

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Zhejiang
      • Hangzhou, Zhejiang, China, 310000
        • Recruiting
        • The Second Affiliated Hospital, Zhejiang University, School of Medicine
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 35 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Age 18-35 years.
  2. Type A, As, or Ad tympanogram in both ears.
  3. Normal hearing in both ears, defined as pure-tone hearing thresholds of ≤20 dB HL at each of the following frequencies: 0.25, 0.5, 1, 2, 4, and 8 kHz.
  4. Willingness to participate and ability to understand and provide written informed consent.

Exclusion Criteria:

  1. History of prolonged exposure to high-intensity noise.
  2. History of prolonged use of ototoxic medications.
  3. History of otologic diseases resulting in permanent changes in hearing thresholds.
  4. Previous diagnosis of hereditary hearing loss or a definite family history of 5. hearing loss.
  5. History of migraine or other neurological disorders that may affect sound tolerance, auditory perception, or study performance.
  6. History of epilepsy, sound-induced seizures, or unexplained episodes of loss of consciousness or convulsions.
  7. Current bothersome tinnitus or symptoms of hyperacusis.
  8. Any other condition that may make participation in the study inappropriate, including psychiatric disorders, cognitive impairment, substance or alcohol dependence, inability to comply with study procedures, or other medical or social factors considered relevant by the investigator.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: AC-BC

Participants will first use in-ear air conduction headphones (AC), followed by open-ear bone conduction headphones (BC), and then bone conduction headphones combined with ear occlusion (BC+Occlusion). Each listening condition will be tested in a quiet environment and under background noise levels of 30, 40, 50, and 60 dB(A). Participants will independently adjust the music volume to a level they consider comfortable and clear.
Behavioral: In-ear Air Conduction Headphones

Participants will wear in-ear air conduction headphones and independently adjust the music volume to a level they consider comfortable and clear for prolonged listening. Testing will be conducted in a quiet environment and under background noise levels of 30, 40, 50, and 60 dB(A). The final selected volume and adjustment behavior will be recorded.

Behavioral: Open-ear Bone Conduction Headphones

Participants will wear open-ear bone conduction headphones and independently adjust the music volume to a level they consider comfortable and clear for prolonged listening. Testing will be conducted in a quiet environment and under background noise levels of 30, 40, 50, and 60 dB(A). The final selected volume and adjustment behavior will be recorded.

Behavioral: Bone Conduction Headphones with Ear Occlusion

Participants will wear open-ear bone conduction headphones while simultaneously inserting in-ear air conduction headphones into both ear canals to create an ear occlusion condition. Music will be delivered exclusively through the bone conduction headphones. Participants will independently adjust the music volume to a level they consider comfortable and clear for prolonged listening. Testing will be conducted in a quiet environment and under background noise levels of 30, 40, 50, and 60 dB(A). The final selected volume and adjustment behavior will be recorded.
Experimental: BC-AC

Participants will first use open-ear bone conduction headphones (BC), followed by in-ear air conduction headphones (AC), and then bone conduction headphones combined with ear occlusion (BC+Occlusion). Each listening condition will be tested in a quiet environment and under background noise levels of 30, 40, 50, and 60 dB(A). Participants will independently adjust the music volume to a level they consider comfortable and clear.
Behavioral: In-ear Air Conduction Headphones

Participants will wear in-ear air conduction headphones and independently adjust the music volume to a level they consider comfortable and clear for prolonged listening. Testing will be conducted in a quiet environment and under background noise levels of 30, 40, 50, and 60 dB(A). The final selected volume and adjustment behavior will be recorded.

Behavioral: Open-ear Bone Conduction Headphones

Participants will wear open-ear bone conduction headphones and independently adjust the music volume to a level they consider comfortable and clear for prolonged listening. Testing will be conducted in a quiet environment and under background noise levels of 30, 40, 50, and 60 dB(A). The final selected volume and adjustment behavior will be recorded.

Behavioral: Bone Conduction Headphones with Ear Occlusion

Participants will wear open-ear bone conduction headphones while simultaneously inserting in-ear air conduction headphones into both ear canals to create an ear occlusion condition. Music will be delivered exclusively through the bone conduction headphones. Participants will independently adjust the music volume to a level they consider comfortable and clear for prolonged listening. Testing will be conducted in a quiet environment and under background noise levels of 30, 40, 50, and 60 dB(A). The final selected volume and adjustment behavior will be recorded.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Self-Adjusted Listening Volume From Quiet to 60 dB(A) Background Noise Levels
Time Frame: During the study visit (approximately 1-2 hours).

The change in final self-adjusted music volume from the quiet condition to the 60 dB(A) background noise condition will be calculated separately for each headphone condition (in-ear air conduction headphones [AC] and open-ear bone conduction headphones [BC]). The change will be calculated as the final volume at 60 dB(A) minus the final volume in the quiet condition. The differences in volume change among the two headphone conditions will be compared.
During the study visit (approximately 1-2 hours).

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Self-Adjusted Listening Volume From Quiet to 30, 40, and 50 dB(A) Background Noise Levels
Time Frame: During the study visit (approximately 1-2 hours).

The change in final self-adjusted music volume from the quiet condition to each background noise level (30, 40, and 50 dB(A)) will be calculated separately for in-ear air conduction headphones (AC) and open-ear bone conduction headphones (BC). The change will be calculated as the final volume at each noise level minus the final volume in the quiet condition. The volume changes between the two headphone conditions will be compared at each noise level.
During the study visit (approximately 1-2 hours).
Final Self-Adjusted Listening Volume at Different Background Noise Levels
Time Frame: During the study visit (approximately 1-2 hours).

The final self-adjusted music volume at quiet condition, 30, 40, 50, and 60 dB(A) background noise levels will be recorded and compared between AC and BC headphones.
During the study visit (approximately 1-2 hours).
Number of Volume Adjustments
Time Frame: During the study visit (approximately 1-2 hours).

The total number of individual volume adjustments made by each participant during each test will be recorded and compared between AC and BC headphones under different background noise conditions.
During the study visit (approximately 1-2 hours).
Total Time Required for Volume Adjustment
Time Frame: During the study visit (approximately 1-2 hours).

The total time from the beginning of volume adjustment to reaching the final self-adjusted listening volume will be recorded and compared between AC and BC headphones under different background noise conditions.
During the study visit (approximately 1-2 hours).
Cumulative Magnitude of Volume Adjustments
Time Frame: During the study visit (approximately 1-2 hours).

The cumulative magnitude of volume adjustments during each test will be calculated as the sum of the absolute values of all individual volume changes, regardless of the direction of adjustment, and compared between AC and BC headphones under different background noise conditions.
During the study visit (approximately 1-2 hours).
Subjective Perception of Vibration During Bone Conduction Headphone Use
Time Frame: During the study visit (approximately 1-2 hours).

Participants will be asked whether they perceive vibration while using bone conduction headphones at their final selected listening volume. The presence or absence of perceived vibration will be recorded under different background noise conditions.
During the study visit (approximately 1-2 hours).

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Self-Adjusted Listening Volume With Ear Occlusion During Bone Conduction Listening
Time Frame: During the study visit (approximately 1-2 hours).

The change in final self-adjusted music volume from the quiet condition to each background noise condition (30, 40, 50, and 60 dB(A)) will be calculated when participants use bone conduction headphones with bilateral ear occlusion (BC+Occlusion). The results will be compared with those obtained using bone conduction headphones without ear occlusion (BC) to evaluate the effect of ear occlusion on noise-induced volume adjustment.
During the study visit (approximately 1-2 hours).
Final Self-Adjusted Listening Volume With Ear Occlusion During Bone Conduction Listening
Time Frame: Time Frame: During the study visit (approximately 1-2 hours).

The final self-adjusted music volume under quiet and background noise conditions (30, 40, 50, and 60 dB(A)) will be recorded during bone conduction headphone use with bilateral ear occlusion (BC+Occlusion) and compared with the corresponding BC condition without ear occlusion.
Time Frame: During the study visit (approximately 1-2 hours).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Second Affiliated Hospital, Zhejiang University, School of Medicine

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 4, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 9, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 12, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 12, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 9, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SAHZU-ACBC-001

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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