[Smogg]

There is a small, circular, piece of cotton/paper in both my headphones from sony.  They're in-ear-montiors, does anyone know what these little circular pieces of paper are?  They're in the nozzle of the in-ear-portion of the headphone....?

 

[namaiki]

Sounds like the IEM filters which let sound through into your ear and prevent ear wax and dirt from going into the speaker.