iPhone Environmental Sound Levels: Troubleshooting No Data Issues
Many users have reported issues with the Health app not displaying environmental sound data after updating to iOS 14 and WatchOS 7. This article explores the problem of missing noise data in the 'Environmental Sounds Category' and the potential causes and solutions.
Globally, noise exposure from occupational and nonoccupational sources is common, and, as a result, noise-induced hearing loss affects tens of millions of people. Occupational noise exposures have been studied and regulated for decades, but nonoccupational sound exposures are not well understood.
Understanding Noise-Induced Hearing Loss (NIHL)
Noise is a ubiquitous environmental exposure, and the most well-understood health impact of noise-noise-induced hearing loss (NIHL)-is among the most common occupational illnesses. Individuals with NIHL may experience a wide variety of social, health, and occupational impacts. These can include communication and relationship difficulties, social withdrawal and isolation, reduced quality of life, depression and mental health issues, reduced fitness-for-duty and loss of employment, and lifelong learning deficits.
Historically, NIHL was a disease that primarily affected adult workers with high exposure to occupational noise. However, in high income countries, industrial and employment trends have resulted in reduced occupational noise exposures in traditionally noisy workplaces, whereas participation in nonoccupational exposures during recreational activities with high sound levels (e.g., listening to music and other audio content) has increased.
Amplified music and music experienced through personal listening devices (e.g., music players and smartphones) are sources of sound exposure that have received great attention in recent years; several studies have indicated that a major source of sound exposure among urban adults was music.
In 1999, the WHO published guidelines for community sound intended to reduce the risk of NIHL. In these guidelines, the recommended exposure limit, intended to eliminate the risk of any NIHL from environmental sound in virtually the entire exposed population, was a 24-h equivalent continuous average (LAEQ) sound pressure level of 70 dBA (i.e., a 70 dBA LAEQ(24h)). Recently, these guidelines have been supplemented by additional guidance intended to reduce the risk of hearing loss from listening to music. The new WHO music-specific recommendation is that an LAEQ(24) exposure of 75 dBA, equivalent to an 8-h average exposure (LEX) of 80 dBA, is sufficiently protective against NIHL for the vast majority of listeners.
While the impacts of NIHL are extensive and widespread and exposure limits have been recommended, information on music and audio content exposure levels and listening patterns, as well as the associated risk of hearing loss, is sparse. Real-world data have historically been difficult to collect due to the logistical and technical challenges in accurate monitoring of the level, duration, and frequency of exposure to music. This has resulted in a reliance on assessments of short-term average or maximum sound levels experienced during listening and survey-based reports of listening durations and frequencies.
Each of these approaches can introduce substantial error into the estimates of music and audio content exposures. Additionally, exposure assessments have typically focused either on music or other types of exposure (e.g., from occupational and nonoccupational activities) and only rarely integrated exposures across these various activities to estimate the total exposure.
The Apple Hearing Study
The Apple Hearing Study is using a dosimetry-based approach to characterize the levels of sound at which participants listen to music and audio content (“headphone audio”). The iPhone is also used to collect app-based audiometry and speech in noise (SIN) test results from participants. The Apple Watch enables the measurement of environmental sound levels and heart rate and activity related measures, which affords the opportunity to explore the impacts of sound on cardiovascular health, a topic on which there is a rapidly growing body of evidence.
By collecting this information from a target sample of 150 000 adult participants, this study will allow for estimates at multiple spatial scales, including the state- and national-levels, of exposure to music and audio content, environmental sound, and the association of these exposures with hearing and heart rate measures.
The study connects and integrates five topical areas: personal characteristics, sound exposure, hearing ability, cardiovascular health, and general health.
Participation occurs virtually through the Apple Research app, which can be downloaded at no cost. The data collection for the study begins after a participant provides informed consent via the research app. The participants have not received any financial incentives for enrollment, participation, or completion of the study.
Eligibility Criteria:
- Residency in the United States and Puerto Rico at the time of the eligibility screening, ascertained via self-report.
- Proficiency in written and spoken English, defined via self-report.
While not a requirement for eligibility, participants using a compatible Apple Watch may contribute activity, heart rate, and environmental sound level data.
The informed consent form is reviewed, signed, and completed within the research app. Once informed consent is obtained, a participant is enrolled in the study. A downloadable copy of the completed consent form is accessible within the research app.
Study User Groups
Following enrollment, the participants are randomly assigned into one of two user groups, which feature common study experiences (“basic”) as well as certain unique experiences (“advanced”). The participants in the basic group have a user interface (UI) in the research app that provides the ability to review exposure level data for the headphone audio levels and environmental sound levels in the health app. The participants in the advanced group have a UI that includes notifications prompting them to review their data in the health app.
Specifically, participants in the advanced group will receive a notification if they experience a high weekly headphone audio (via iPhone) or environmental sound (via Apple Watch) exposure level that meets or exceeds a 7-day LEQ >80 dBA for >40 h or have an acute exposure >97 dBA LEQ for >30 min from headphone audio or environmental sound. This LEQ was adopted based on WHO recommendations. The notification will prompt the participant to review this exposure level data in their health app and answer questions related to their exposure.
Survey questions will ask the user to confirm that they reviewed their data and then focus on the perceived accuracy of the measurement, whether or not they used any hearing protection (e.g., hearing protection worn at a rock concert), and any intended listening behavior change resulted from their data review. The advanced group participants are also prompted to complete a short survey and an abbreviated hearing test, both triggered by acute exposures to loud sound.
Prior to the launch of the study, it was anticipated that a minority of the participants would routinely exceed our exposure levels for notifications and triggered hearing tests and, as such, favored randomization into the advanced user interface group (40/60 distribution of basic/advanced UI groups) to increase the likelihood that a sufficient number of participants will be provided with notifications and asked to complete the associated hearing tests.
Data Collection and Flow
Once consent has been provided by a participant and they are enrolled in the study, collection of the data types covered in the informed consent begins. The primary data source for the study is the iPhone, which runs the research and health apps .The research app is used to review and collect participant responses to surveys questions and tasks such as hearing tests. The Apple Watch is used to measure the ambient sound pressure level, and the iPhone uses these measurements in combination with the duration of exposure in a participant's environment to compute LEX.
The health app securely stores data on the device and select health app data, such as activity and heart related data, may be shared with permission to the research app. During participation, the research app collects and shares study data with Apple's secure cloud platform. The data are constantly and asynchronously uploaded, making the data dynamic in nature with large volumes of information continuously flowing in. The participants receive notifications when a study activity is being requested of them.
Collected Measures
The measures collected as part of the Apple Hearing Study are shown in Table 1.
| Topical area | Measure | Group | Source | Temporal resolution | Measurement duration (each) |
|---|---|---|---|---|---|
| Personal characteristics | Demographics | B, A | Survey | Several times/year | <5 min |
| Sound exposure | Environmental sound level (dBA) | B, A | Apple Watch | Average 30 s intervals, 5 s intervals when > 80 dBA | NA |
| Sound exposure | Headphone audio exposure (dBA) | B, A | iPhone | Average every 5 s | NA |
| Hearing ability | Scheduled tone audiometry | B, A | iPhone | Several times/year | 10 min |
| Cardiovascular health | Heart rate | B, A | Apple Watch | Average every 5 min | NA |
| General health | COVID-19 medical history | B, A | Survey | Every two months | 5 min |
| General health | Perceived stress level (Perceived Stress Scale-4, PSS4) | B, A | Survey | Every two months | <5 min |
The data collection for each of the five topical areas occurs for each participant over the entire duration of the study via iPhone, Apple Watch, or survey and at temporal resolutions ranging from several seconds to annually. The research activities are distributed to minimize the burden on participants at any given point of time in the study, and participants may opt not to complete any tasks.
Troubleshooting Steps
Here are some troubleshooting steps to address the issue of missing environmental sound levels data:
- Unpair and Re-pair Apple Watch: This can help reset the connection and data syncing between your Apple Watch and iPhone.
- Toggle Noise Logging: In the Health app settings, toggle the noise logging for headphones and ambient noise off and on.
- Restart Devices: Restart your iPhone and Apple Watch to refresh the system processes.
Viewing Noise Data in the Health App
When you pair Apple Watch with your iPhone and set up the Noise app on Apple Watch, environmental sound levels are automatically sent from Apple Watch to the Health app on iPhone.
To view the details about a noise notification, do the following:
- Go to the Health app on your iPhone.
- Tap Summary at the bottom left, tap the notification near the top of the screen, then tap Show More Data.
To see your exposure to environmental noise levels over time:
- Go to the Health app on your iPhone.
- Tap at the bottom right, then tap Hearing.
- Tap Environmental Sound Levels, then do any of the following: View exposure levels over a time period: Tap the tabs at the top of the screen.