Hearing Loss, Noise-InducedAHSNCT04172766
Apple Hearing Study
An observational study of Hearing Loss, Noise-Induced and Hearing Loss, run by Apple Inc. at 1 site in United States.
Trial summary
The Apple Hearing Study is a partnership between the University of Michigan and Apple to study sound exposure and its impact on hearing health. This groundbreaking study will advance the understanding of how hearing could be impacted over time by exposure to sound at certain levels. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Hearing Loss, Noise-Induced, Hearing Loss, Tinnitus
- How many people
- 300,000 participants
- Where
- 1 siteUnited States
- Study dates
- 14 Nov 2019to Dec 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Adults age 18 or older that live in the U.S. or U.S. territories and have iPhone with the Research app installed.
Who may be able to join
- Age ≥ 18 years at time of eligibility screening, ascertained from self-reported date of birth. Potential subjects in the states of Alabama and Nebraska must be 19 or older (legal age of consent in these states), and 21 and older for any subjects in Puerto Rico.
- Live in the United States of America at time of eligibility screening, ascertained from self-report.
- Proficient in written and spoken English, defined by self-report.
- Participants must NOT share their iCloud account, iPhone or other devices such as Apple Watch with anyone else as this would make it challenging for researchers to use their information.
- Possession of the following, ascertained from automatic hardware/software/device pairing check:
- iPhone with iOS versions capable of supporting the Research app used to complete screening eligibility.
- Optional: Apple Watch (any model) paired with iPhone; an Apple Watch Series 4 or later is required to share environmental sound levels.
Who cannot join
None listed.
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Michigan School of Public Health
Ann Arbor, Michigan, 48109
About this study
Official title: Apple Hearing Study: Characterization of Headphone Audio Levels, and Optional Wristwatch-Based Environmental Sound Levels, With Variable User Interface
The Apple Hearing Study is a partnership between the University of Michigan and Apple to study sound exposure and its impact on hearing health. This groundbreaking study will advance the understanding of how hearing could be impacted over time by exposure to sound at certain levels. The investigators will measure headphone and environmental sound exposures over time among participants, and determine how these exposures impact hearing and stress levels. US residents who own an iPhone, download the Apple Research app and consent to participate will be randomly assigned to two groups, one with a "Basic" user interface in the Research app, and one with an "Advanced" user interface. Users in the "Advanced" group will receive additional information about their exposures and be given additional surveys and hearing tests based on their music and environmental sound exposures. The study will provide investigators with a better understanding of listening behavior and its overall impact on hearing health. This information will in turn help guide public health policy and prevention programs designed to protect and promote hearing health in the US and globally.
- Conditions
- Hearing Loss, Noise-Induced, Hearing Loss, Tinnitus
- Keywords
- Hearing Loss, Noise Exposure, Noise Induced Hearing Loss, Listening Volume, Environmental Noise, Music, Audiometry, Speech-in-Noise, Hearing Ability, Headphones, Headphone audio level, Ambient noise, Occupational noise, Heart rate, Tinnitus
- Medical subject headings
- Hearing Loss, Noise-Induced, Hearing Loss, Tinnitus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Cohort | Participants will be asked to read and sign the study ICF within the app if they agree and are willing to participate. After providing informed consent to participate, participants will be directed to select which data they want to share from the Health App via HealthKit and SensorKit to the Research app. All Research app users are asked to complete contact information and demographic questions that may be common across multiple Research app studies, such as age, race, sex, location of residence, and socioeconomic status. Participants will be asked to complete surveys approximately every other month for a total of about 1.5 hours over the entire year. Participants will be asked to complete three types of hearing tests 2-6 times per year; Interactive Tinnitus Tasks, Pure Tone Audiometry, and Speech in Noise. Participants will also be requested to complete brief on-demand surveys following high sound level measurements from headphones or the watch, at most monthly. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Headphone audio level patterns
For the entire cohort over various timeframes
Measured: From enrollment to the end of followup at 10 years
Difference in Headphone Audio Level patterns
This will include assessment of sound pressure level and time at baseline and over the duration of the study.
Measured: From enrollment to the end of followup at 10 years
Association between Headphone Audio Level patterns and Pure Tone Audiometry
Analysis will occur for each tested frequency (dB HL at 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4kHz, and 8 kHz assessed for both ears) for both ears at baseline and over the duration of the study.
Measured: From enrollment to the end of followup at 10 years
Association between Headphone Audio Level patterns and Speech in Noise
Analysis will assess the speech recognition threshold and it's relationships with HAL at baseline and over the duration of the study
Measured: From enrollment to the end of followup at 10 years
Association between Headphone Audio Level patterns and tinnitus matching
At baseline and over the duration of the study
Measured: From enrollment to the end of followup at 10 years
Association between general health and individual characteristics and sound levels and/or audiometry tasks
Headphone Audio Levels will be assessed as the sound level and the audiometry tasks assessed will be Pure Tone Audiometry, Speech in Noise, and tinnitus matching
Measured: From enrollment to the end of followup after 10 years
Change from baseline to final audiometry
Including both Pure Tone Audiometry and Speech in Noise
Measured: From enrollment to the end of followup after 10 years
Change from baseline in abbreviated Pure Tone Audiometry following high headphone audio level notification
This comparison will occur for two frequencies (1 kHz and 4 kHz for both ears) within 24 hours of acute loud Headphone Audio Level exposure (LEQ equivalent to >97 dBA for >30 minutes)
Measured: From enrollment to the end of followup after 10 years
Headphone Audio Level association with baseline survey questions
This will includes questions about typical headphone us, typical environmental exposures, and hearing ability.
Measured: From enrollment to the end of followup after 10 years
Baseline Audiometry association with baseline survey questions
Baseline Audiometry includes both Pure Tone Audiometry and Speech in Noise. Survey questions include those regarding typical headphone use, typical environmental exposures, and hearing ability.
Measured: From enrollment to the end of followup after 10 years
Final Audiometry association with end-of-study survey questions
Final Audiometry includes Pure Tone Audiometry and Speech in Noise. The end-of-study survey questions include typical headphone use, typical environmental exposures, and hearing ability.
Measured: At the end of followup after 10 years
Change in survey questions
Survey questions regarding exposure changes over the course of the study
Measured: From enrollment to the end of followup after 10 years
Association between hearing ability and changes in hearing health and related health conditions
Hearing ability is evaluated both as perceived and evaluated. Changes in hearing health include audiometry and tinnitus. Related health conditions include items such as cognition, sleep, mental health, activity, mobility, and more.
Measured: From enrollment to the end of followup after 10 years
Descriptive assessment of participant use and experience
Experience with hearing related tools and device
Measured: From enrollment to the end of followup after 10 years
Secondary outcomes (10)
Difference in Environmental Sound Level Patterns
Including sound pressure level and time at baseline and over the duration of the study. This outcome is only among participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Association between Headphone Audio Levels and Environmental Sound Level patterns
This outcome is only among participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Association between Environmental Sound Level patterns and Pure Tone Audiometry.
At baseline and over the duration of the study. This outcome is only among Participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Association between Environmental Sound Level patterns and Speech in Noise
At baseline and over the duration of the study. This outcome is only among Participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Association between Environmental Sound Level patterns and tinnitus matching task
At baseline and over the duration of the study. This outcome is only among Participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Association between general health and personal characteristics and sound levels and hearing tasks
Sound levels include Environmental Sound Levels. Hearing tasks includes Pure Tone Audiometry, Speech in Noise, and Tinnitus matching. This outcome is only among Participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Change from baseline in abbreviated Pure Tone Audiometry following loud environmental noise notification
This assessment will be for two frequencies (1 kHz and 4 kHz for both ears) tested within 24 hours of acute loud Environmental Sound Level exposure (LEQ equivalent to >97 dBA for >30 minutes). This outcome is only among Participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Assess reported participant experience
Experience will be assessed via survey delivered with a notification after a prolonged loud environmental sound level exposure (LEQ equivalent to >80 dBA for >40 hours). This outcome is only among Participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Association between heart rate measures and Headphone Audio Level patterns
This will include heart rate during activity (as assessed by logged Workouts and Active Energy trends by Watch). This outcome is only among participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Association between heart rate measures and Environmental Sound Level patterns
This includes heart rate during activity (as assessed by logged Workouts and Active Energy trends by Watch). This outcome is only among participants that use Apple Watch.
Measured: From enrollment to the end of followup after 10 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Nov 2019
- Study start14 Nov 2019
- Primary completion31 Aug 2029 (estimated)
- Study completionDec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Hearing Loss, Noise-InducedStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 300,000 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Apple Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- World Health Organization
- Responsible party
- Principal investigator, Richard Neitzel, University of Michigan
- Investigators
- Richard L Neitzel, PhD, MS, CIH, Principal investigator, University of MichiganLauren M Smith, MS, MPH, Study director, University of MichiganJoyce M Daniels, MA, Study chair, University of Michigan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04172766
- Sponsor's protocol ID
- Pro00037864
- Other IDs
- HUM00167885
- Acronym
- AHS
- Status last verified
- Mar 2026
- First submitted
- 13 Nov 2019
- Last updated
- 19 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: N/A - no plan to share
Publications
Smith LM, Wang L, Mazur K, Carchia M, DePalma G, Azimi R, Mravca S, and Neitzel RL. Impacts of COVID-19-related social distancing measures on personal environmental sound exposures. Environmental Research Letters. Oct 2020. 15.10: 104094. https://iopscience.iop.org/article/10.1088/1748-9326/abb494
Neitzel RL, Smith L, Wang L, Green G, Block J, Carchia M, Mazur K, DePalma G, Azimi R, Villanueva B. Toward a better understanding of nonoccupational sound exposures and associated health impacts: Methods of the Apple Hearing Study. J Acoust Soc Am. 2022 Mar;151(3):1476. doi: 10.1121/10.0009620.
PubMed 35364926
Study at a glance
From the registry record, last updated by the sponsor on 19 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Apple Hearing Study: Characterization of Headphone Audio Levels, and Optional Wristwatch-Based Environmental Sound Levels, With Variable User Interface
- ClinicalTrials.gov ID
- NCT04172766
- Acronym / sponsor ID
- AHS / Pro00037864
- Conditions
- Hearing Loss, Noise-Induced, Hearing Loss, Tinnitus
- Keywords
- Hearing Loss, Noise Exposure, Noise Induced Hearing Loss, Listening Volume, Environmental Noise, Music, Audiometry, Speech-in-Noise
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 300,000 participants (estimated)
- Lead sponsor
- Apple Inc.Industry (pharma, biotech, devices)
- Collaborators
- World Health Organization
- Study start
- 14 Nov 2019 (actual)
- Primary completion
- 31 Aug 2029 (estimated)
- Study completion
- Dec 2029 (estimated)
- First posted
- 21 Nov 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The Apple Hearing Study is a partnership between the University of Michigan and Apple to study sound exposure and its impact on hearing health. This groundbreaking study will advance the understanding of how hearing could be impacted over time by exposure to sound at certain levels. The investigators will measure headphone and environmental sound exposures over time among participants, and determine how these exposures impact hearing and stress levels. US residents who own an iPhone, download the Apple Research app and consent to participate will be randomly assigned to two groups, one with a "Basic" user interface in the Research app, and one with an "Advanced" user interface. Users in the "Advanced" group will receive additional information about their exposures and be given additional surveys and hearing tests based on their music and environmental sound exposures. The study will provide investigators with a better understanding of listening behavior and its overall impact on hearing health. This information will in turn help guide public health policy and prevention programs designed to protect and promote hearing health in the US and globally.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Cohort | – | –Participants will be asked to read and sign the study ICF within the app if they agree and are willing to participate. After providing informed consent to participate, participants will be directed to select which data they want to share from the Health App via HealthKit and SensorKit to the Research app. All Research app users are asked to complete contact information and demographic questions that may be common across multiple Research app studies, such as age, race, sex, location of residence, and socioeconomic status. Participants will be asked to complete surveys approximately every other month for a total of about 1.5 hours over the entire year. Participants will be asked to complete three types of hearing tests 2-6 times per year; Interactive Tinnitus Tasks, Pure Tone Audiometry, and Speech in Noise. Participants will also be requested to complete brief on-demand surveys following high sound level measurements from headphones or the watch, at most monthly. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Adults age 18 or older that live in the U.S. or U.S. territories and have iPhone with the Research app installed.
Key inclusion criteria (7 listed)
- Age ≥ 18 years at time of eligibility screening, ascertained from self-reported date of birth. Potential subjects in the states of Alabama and Nebraska must be 19 or older (legal age of consent in these states), and 21 and older for any subjects in Puerto Rico.
- Live in the United States of America at time of eligibility screening, ascertained from self-report.
- Proficient in written and spoken English, defined by self-report.
- Participants must NOT share their iCloud account, iPhone or other devices such as Apple Watch with anyone else as this would make it challenging for researchers to use their information.
- Possession of the following, ascertained from automatic hardware/software/device pairing check:
Key exclusion criteria (0 listed)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Headphone audio level patterns
Time frame: From enrollment to the end of followup at 10 years
For the entire cohort over various timeframes
Difference in Headphone Audio Level patterns
Time frame: From enrollment to the end of followup at 10 years
This will include assessment of sound pressure level and time at baseline and over the duration of the study.
Association between Headphone Audio Level patterns and Pure Tone Audiometry
Time frame: From enrollment to the end of followup at 10 years
Analysis will occur for each tested frequency (dB HL at 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4kHz, and 8 kHz assessed for both ears) for both ears at baseline and over the duration of the study.
Association between Headphone Audio Level patterns and Speech in Noise
Time frame: From enrollment to the end of followup at 10 years
Analysis will assess the speech recognition threshold and it's relationships with HAL at baseline and over the duration of the study
Association between Headphone Audio Level patterns and tinnitus matching
Time frame: From enrollment to the end of followup at 10 years
At baseline and over the duration of the study
Association between general health and individual characteristics and sound levels and/or audiometry tasks
Time frame: From enrollment to the end of followup after 10 years
Headphone Audio Levels will be assessed as the sound level and the audiometry tasks assessed will be Pure Tone Audiometry, Speech in Noise, and tinnitus matching
Change from baseline to final audiometry
Time frame: From enrollment to the end of followup after 10 years
Including both Pure Tone Audiometry and Speech in Noise
Change from baseline in abbreviated Pure Tone Audiometry following high headphone audio level notification
Time frame: From enrollment to the end of followup after 10 years
This comparison will occur for two frequencies (1 kHz and 4 kHz for both ears) within 24 hours of acute loud Headphone Audio Level exposure (LEQ equivalent to >97 dBA for >30 minutes)
Headphone Audio Level association with baseline survey questions
Time frame: From enrollment to the end of followup after 10 years
This will includes questions about typical headphone us, typical environmental exposures, and hearing ability.
Baseline Audiometry association with baseline survey questions
Time frame: From enrollment to the end of followup after 10 years
Baseline Audiometry includes both Pure Tone Audiometry and Speech in Noise. Survey questions include those regarding typical headphone use, typical environmental exposures, and hearing ability.
Final Audiometry association with end-of-study survey questions
Time frame: At the end of followup after 10 years
Final Audiometry includes Pure Tone Audiometry and Speech in Noise. The end-of-study survey questions include typical headphone use, typical environmental exposures, and hearing ability.
Change in survey questions
Time frame: From enrollment to the end of followup after 10 years
Survey questions regarding exposure changes over the course of the study
Association between hearing ability and changes in hearing health and related health conditions
Time frame: From enrollment to the end of followup after 10 years
Hearing ability is evaluated both as perceived and evaluated. Changes in hearing health include audiometry and tinnitus. Related health conditions include items such as cognition, sleep, mental health, activity, mobility, and more.
Descriptive assessment of participant use and experience
Time frame: From enrollment to the end of followup after 10 years
Experience with hearing related tools and device
10 secondary outcomes
Difference in Environmental Sound Level Patterns
Time frame: From enrollment to the end of followup after 10 years
Association between Headphone Audio Levels and Environmental Sound Level patterns
Time frame: From enrollment to the end of followup after 10 years
Association between Environmental Sound Level patterns and Pure Tone Audiometry.
Time frame: From enrollment to the end of followup after 10 years
Association between Environmental Sound Level patterns and Speech in Noise
Time frame: From enrollment to the end of followup after 10 years
Association between Environmental Sound Level patterns and tinnitus matching task
Time frame: From enrollment to the end of followup after 10 years
Association between general health and personal characteristics and sound levels and hearing tasks
Time frame: From enrollment to the end of followup after 10 years
Change from baseline in abbreviated Pure Tone Audiometry following loud environmental noise notification
Time frame: From enrollment to the end of followup after 10 years
Assess reported participant experience
Time frame: From enrollment to the end of followup after 10 years
Association between heart rate measures and Headphone Audio Level patterns
Time frame: From enrollment to the end of followup after 10 years
Association between heart rate measures and Environmental Sound Level patterns
Time frame: From enrollment to the end of followup after 10 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Mar 2026.
- Results publicationSmith LM, Wang L, Mazur K, Carchia M, DePalma G, Azimi R, Mravca S, and Neitzel RL. Impacts of COVID-19-related social distancing measures on personal environmental sound exposures. Environmental Research Letters. Oct 2020. 15.10: 104094. https://iopscience.iop.org/article/10.1088/1748-9326/abb494
- Results publication: PubMed 35364926Neitzel RL, Smith L, Wang L, Green G, Block J, Carchia M, Mazur K, DePalma G, Azimi R, Villanueva B. Toward a better understanding of nonoccupational sound exposures and associated health impacts: Methods of the Apple Hearing Study. J Acoust Soc Am. 2022 Mar;151(3):1476. doi: 10.1121/10.0009620.
- UM Study WebsiteLink provided by the sponsor.
- Individual participant dataSharing planned: No. N/A - no plan to share
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Richard L Neitzel, PhD, MS, CIH principal investigator
University of Michigan
Lauren M Smith, MS, MPH study director
University of Michigan
Joyce M Daniels, MA study chair
University of Michigan
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Hearing Loss, Noise-Induced and Hearing Loss, run by Apple Inc. at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 0 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 19 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Headphone audio level patterns (time frame: From enrollment to the end of followup at 10 years). The study lists 14 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04172766, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Mar 2026.