by Daniel Fink, MD, Chair, The Quiet Coalition
Patently Apple has written about the technology behind Apple’s newest patent for in-ear sound level monitoring, i.e., sound pressure level monitoring. Having a patent approved is a notable achievement, and we congratulate Apple on developing the new technology and the obtaining the patent for it.
I have one problem with the post. Namely, it understates or actually distorts what is known about safe noise exposure levels to prevent noise-induced hearing loss. The post states:
For instance, extended exposure to sounds at or above 85 dB may cause temporary or permanent hearing loss in one or both ears. Therefore, some organizations (e.g., the National Institute for Occupational Safety and health (NIOSH) has recommended that worker exposure to ambient noise be controlled below a level equivalent to 85 dBA for eight hours to minimize occupational NIHL.
It also says that “[r]ecently, the World Health Organization has released hearing health safety standards that limit the maximum sound output of a headset to 85 dBA.” Decibels are abbreviated as dB, and A-weighted decibels, adjusting dB measurements to reflect the frequencies heard in human speech, are dBA.
The problem is that there is no such thing as temporary auditory damage–temporary hearing loss indicates permanent auditory damage–and the auditory injury threshold is only 75-78 dBA. The WHO recommends only 1-hour exposure at 85 dBA to prevent NIHL, and the only evidence-based noise level to prevent NIHL is a time-weighted average of 70 dB for 24 hours.
That’s the information Patently Apple needs to tell its readers, and its what Apple should tell users of its iPhones, iPods, and iPads, EarPods, and AirPods too.
Unfortunately, looking for a safe personal listening device is like looking for a safe cigarette. Try as one might, one won’t find one.
And with the average personal audio system user listening 4.5 hours a day, I’m pretty sure anyone using one of these devices will develop NIHL.