Apple introduced the ability to track your noise level exposure on the Apple Watch back in 2019. The company also launched three clinical research studies alongside that feature, including one to examine hearing health. Now, a little over a year later, Apple’s sharing some preliminary results in time for World Hearing Day.
For the Apple Hearing Study, Apple partnered with the University of Michigan to look at how daily sound exposure can impact hearing over time. In a briefing, Dr. Rick Neitzel from the University of Michigan noted that the “thousands” of participants in the study volunteered their data and, in addition to regular questionnaires, participated in regular hearing tests. The study also looked at noise exposure from headphones and wasn’t necessarily limited to data collected from the Apple Watch. Headphone exposure data, for example, could also be collected from the iPhone and iPad. That said, the researchers were able to get more detailed data from watch users, including environmental noise, heart rate, heart rate variability, and exercise.
According to Neitzel, one intriguing takeaway from the early data is that one in five participants experienced some kind of hearing loss, according to World Health Organisation guidelines, and that there seems to be a link between chronic environmental noise and cardiovascular disease. Also, nearly 50% of participants currently work, or previously worked, in a loud workplace. Another surprising tidbit was that despite covid-19 lockdowns, many participants still had high environmental noise exposure (though overall noise exposure was cut nearly in half). About 10% of participants also had been professionally diagnosed with hearing loss, but despite that diagnosis, 75% of them weren’t using assistive support such as hearing aids or cochlear implants. Another 10% had average headphone sound exposure exceeding weekly WHO limits, and 20% had daily exposure above daily WHO limits. Another sobering finding was that 25% regularly experienced a ringing in the ears that could be tinnitus a few times per week and that nearly 50% hadn’t had their hearing tested by a professional in at least a decade.
The findings are actually pretty impressive when you consider the scale and the detailed data that wearables can report with just passive health-monitoring. A major problem that can occur with health research is that the findings may come from a limited sample that may not be indicative of the general population or have an inherent bias (i.e., not enough BIPOC subjects, etc.) With wearables, you can actually conduct continuous research with a much, much larger slice of the population. The Apple Heart Study, for example, managed to get 400,000 participants in eight months, making it the largest virtual study to date.
On that front, Neitzel said that he believes that the participants in the Apple Hearing Study are overall accurately representative of the general population. He also noted that access to location data, for example, can help researchers look for more esoteric patterns. For example, researchers can now ask questions like, “Is hearing loss worse in an area with more air pollution?”
The Apple Hearing Study is still ongoing, and Neitzel noted there’s still more to learn. In particular, Neitzel pointed to understanding how typical noise exposure and headphone listening patterns could impact future hearing health, including tinnitus, as well as further exploring the relationship between hearing and cardiovascular health. In the meantime, however, it’s probably a good idea if we all just lowered the volume on our headphones.