The small holes in earphones serve the same purpose as the ones in home stereo speakers and car stereo speakers boxes.
It’s usually a tuned port to assist the speaker in producing more bass with less energy.
Speakers are designed to accomplish one task, and that is to move air. The simpler it is for the speaker to move, the more air it can displace.
This is especially true for lower frequencies, also known as bass, which requires the speaker to move more extensively.
Headphones and earbuds have small vent holes, or “ventilation ports,” on the exterior to make it easier for the speaker to move.
These ports enable air to flow in and out behind the speaker as it pushes and pulls air toward the ear.
They equalize pressure between the inside and outside of the earphone’s speaker driver.
Without the ventilation ports, the speaker driver would be sealed, which would cause a build-up of pressure and result in distorted sound.
The small holes also help to reduce the chances of the earphones producing a “pop” sound when inserted or removed from the ear.
These holes allow air to move in and out, improving the acoustics of the earphones and keeping them in place by creating a vacuum effect.
This vacuum also eliminates any thumping sounds from the cord moving around.
So next time you see these vent holes on earphones, remember the superior engineering behind creating these small but essential ventilation ports.
Unfortunately, these holes allow external noise to enter your earpiece but don’t affect the sound quality much.
Note that all the tiny holes you see on the earpiece of your headphone/earphone may not be vent holes.
Some may be there for a mic to capture external noise for noise-canceling purposes.
Are you interested to know more about that?
I’ve written a whole article about noise cancellation in headphones.
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