Audio Hiss since FW 11 on 8800 series

[Adam Pawlowski]

Has anyone else noticed a white noise hiss with the 8800 series phones after moving from 10 firmware to 11 firmware?

It seems like someone took the gain control and broke it causing the audio to sound overdriven. The worst part about it is this white noise hiss that's present audibly now. The speaker phone particularly sounds like it is ready to rattle apart and I don't know what has changed.

[Jonathan Unger]

I am not sure specifically about the "hissing" noise, but if you are running 11.5 code and the phones are negotiating OPUS, you may be experiencing this bug:

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvc76073

[Mohammed al Baqari]

Hi, Did you upgrade the phone firmware part of cucm upgrade. If so, try to revert back to the inactive firmwrae and see if it fixes the problem. There are couple of bugs listed on audio quality with 88xx phones

[Adam Pawlowski]

We did let it roll to 11.7 with the UCM upgrade, from a 10 iterant (10-6?). Some of the hardware revisions of the 8851 are listed as not being able to downgrade below 11.5 but I don't know if we have any of those yet.

I'll give it a try when I can to lab flipping back to 10 something, but I see 12 is out now too.