I was listening on the earbuds it came with earlier and didn't notice anything when using Spotify. Just now used it with my Audio Technica ATH-M50s and still no hissing or breaking up with Spotify. Spotify and Google Music is all I use and I stream all of my music. Not sure if that makes a difference.
-HTC One (M8)
iPhone 3GS | iPhone 4 | Infuse 4G | Galaxy SII | Galaxy Nexus | Nexus 7 | Note 2 | G2