Comment 29 for bug 1654448

@vanvugt I do have both cable types (with and without cable mic). In testing the Quiet Comfort 15s:

Bose CQ 15 w/ normal cable - The hiss is present with 0 dB headphone mic gain, but far more reduced than the Sony earbuds. It is almost unnoticeable. If I weren't trying to hear it, I'd miss it.

Bose CQ 15 w/ mic cable - I cannot detect any hiss present with 0 db gain.

@esokrarkose I'm sorry I misunderstood what you were saying about your experience with the hiss. I thought you were saying it only happened while playing a sound. I too experience the constant hiss with my earbuds. I don't doubt the hiss in normal headphones.

The Bose CQs do produce the hiss with one cable type. It is barely noticeable and much more subdued than the earbuds. I'm not sure what Bose does if anything with the sound signal coming from the headphone jack. Maybe it's just reduced due to higher quality speakers than say my earbuds. As I understand it the noise cancellation is meant for external sounds, but like you said, maybe it plays a role in making the hiss less audible. The noise cancellation itself does produce a level of white noise.