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Inspired by this article, where a Texas family claim that an "Amber Alert" on their son's Airpods caused his eardrum to rupture.

https://www.dailymail.co.uk/news/article-10830803/Boy-suffered-ruptured-ear-drum-hearing-loss-Apple-AirPods-blared-Amber-Alert.html

According to this, sound levels starting from 165 decibels would cause eardrum rupture:

When the loudness of a sound exceeds 165 dB, the pressure wave may also rupture the tympanic membrane.

https://evidence.unboundmedicine.com/evidence/view/EBMG/457351/all/Acute_acoustic_trauma#:~:text=An%20intense%20sound%20wave%20will,also%20rupture%20the%20tympanic%20membrane.

Question: Are the Apple Airpods physically capable of producing 165 decibels of sound?

user47776
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    So what did your research show for the max power output of the Airpods? – Solar Mike May 08 '24 at 14:24
  • Measuring the loudness of earbuds is actually quite difficult, because it depends heavily on the geometry of how it's inserted. I believe they actually use human shaped dummy ears for testing this. – Drew May 10 '24 at 15:39

2 Answers2

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The short answer, "No."

But since this is the Engineering Stack Exchange, I'll give a more substantial answer.

A little research shows that Apple Airpods have a 0.093Wh battery and can play "up to" five hours. Experience shows that if you play loud music, you get less life on the batteries. To make the numbers come out even, I'll say at high volume, you can get no more than 3.72 hours. To consume a 0.093 Wh battery in 3.72 hours, the Airpods would be using 0.025 watts.

We find on the web that decibel measure is a logarithmic ratio of sound intensity, referenced to $10^{-12}$ $watts/meter^2$. (Technically, the logarithmic ratio times 10.) If all of the sound produced by a 100% efficient 0.025 watt amplifier went into a 1$cm^2$ ear canal, that would give a sound pressure level of:

$SPL= \frac{(0.025 watts)}{1 cm^2} X \frac{{(100cm)}^2}{1 meter^2}$

Simplifying,

$SPL=\frac{0.025 watts X 10^4 }{meter^2} $

for a sound pressure level of: SPL=250 $\frac{watts}{meter^2}$

Finding 10 times the logarithmic ratio of $10^{-12}$ $\frac{watts}{meter^2}$ gives:

$dB=10*log(\frac{250}{10^{-12}})$

or:

$dB= 144$

Enough to damage your hearing very quickly but not up to the 160dB that the reference says is required to burst ear drums.

If you don't like those numbers, I'll produce some others. Assuming we use up the entire 0.093 Wh battery in 0.93 hours (0:55:48) (to make the numbers come out even) that would mean the power is 0.1 watts. Running the same calculations gives 1000 $\frac{watts}{meter^2}$ which gives 150 dB, still short of the 160 dB "required."

I don't doubt that Airpods can do a number on your hearing but I have trouble believing that the Airpods (from the article) "'ripped open' his eardrum." I don't have Airpods but my earphones came with a warning about sound levels. If you try hard enough, you can injure yourself with anything. What's more, if you find the right lawyer, you can sue a big company for anything, as well.

user1683793
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I think we can agree that there is no practical reason to design the airpod to hit 165 dB, therefore Apple would be making design compromises to hit a target that is irrelevant. The main way to increase the SPL of a speaker of a given diameter is to make it move further, making the Airpod bigger and heavier. Alternatively make the speaker bigger in diameter, again making the Airpod bigger and heavier. Does that sound likely?

165 dB is about 0.5 psi, the pressure increase you'd get from diving 3 ft below the surface while holding your breath. I doubt that would rupture a healthy eardrum, since I regularly duck dive down to 10-15 feet.

Greg Locock
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