Annoying whitenoise sound coming from snd_hda enabled chipset

[Alexander Motin]

Yoshihiro Ota wrote:
> The problem is some mysterious sound like szzzz..... in very low tone and low volume.
> However, it is noticeable and somewhat destructing.
> I usually use 7.1-RELEASE, but as 8.0 being in BETA, I installed 8-BETA1 and BETA2.
> Both of these versions has this noise.
> 
> The noise is very much like the same noise I experienced back in February.
> At that time, you, Alexander, fixed the problem.
> I had had used 8-CURRENT until end of April but I was away until this time.
> Because the symptom was smiler, I decided to reply to the old e-mail chain.

Sorry, I don't remember what have I done that time, if it really was me. 
I have reread that thread and haven't found anything except assumptions 
that it can be radio interference due to low quality power filtering or 
something alike. May be "szzzz..." is just the sound of your disk, CPU, 
CPU bus, some power converter, or whatever else. It may depend for 
example on powerd running or system load, or C-state used or whatever 
else unrelated.

-- 
Alexander Motin