What Is This Noise?

Sounds like the type of noise some manufacturers add to their product demos. Not something Cakewalk ever did and I doubt BandLab does either.

Interesting. If it's a synth, I may be able to configure it and solve the problem. I'll have to watch my synths while it's playing, and see if I can narrow it down.

My suspicion is on the free Kontakt Player, although I'm not sure why. Just a hunch., So if anyone has any info on that, please let me know. Like, how to configure it and such.

Unfortunately the problem remains. I stress again that this did not happen with 8.5 Studio, only Home Studio (the freebie people were recently downloading) and CbB. So this would tend to argue that it is some setting in these newer programs that is the culprit. Or possibly an incompatibility between these program and one or more of my synths.

Good thought Kamikaze, will do. (Why didn't I think of that?).

Actually, I don't use much in the way of vsts. For my current project, an orchestral piece, here is what I'm using:
 
VSTi: 1 Play, 1 Aria, 1 Vienna, 1 Dim. Pro, 2 Kontakts with Cinematic Strings; 3 Studio Inst with Strings. All have just a handful of insts. on them.
 
vsts: 1 Spaces, 1 Sontius Compressor, 1 Tube Leveler.
 
The VSTi go to the Reverb bus, with Spaces. Spaces goes to the Mix bus, where the Compressor and Tube Leveler are.
 
That's it. Although sometimes I turn the LP64 EQ on, but usually I leave that for mastering.

One small step at a time - does it happen in exactly same place(s) every time you play back or does it appear randomly?

Sorry! you're right, I need to provide more info, and try your suggestions.
 
First, it appears to be random. Hit or miss. Today on my run through my project, to see how what I did last night sounds, it didn't happen at all.
 
I will do the following to troubleshoot: the next time it happens I'll stop play there and note what synths and instruments were going. I'll do that every time I hear the noise. Hopefully, a pattern will emerge and I'll be able to zero in on the culprit.
 
I appreciate the help.

Why use Freeze? Muting should be sufficient.

I beleieve Dim Pro needs you to activate by running as Administrator. 
 
OK, Random as said is real hard to pin down. 
 
What I was doing in the case of Sonar randomly crashing was keep a notebook and write down what was happening at the time of the crash. 
For a while I thought it was a 32 bit VST I was still using because it was in all projects that crashed. Then one day I had a crash without that VST so back to square one.
 
WHat seem to stop the crashes for me ( and others too) was to make sure and save A LOT.
Like every 10 little edits. The crashes have almost stopped since then with only once and guess what,, I hadn't saved for a long time while editing. 
 
You problem is different but sort of the same because Random is tricky. 
So start making notes. 
I would for sure try using different plug ins. 

Yeah, random and intermittent. Which makes it hard even to devise a strategy. But if I can determine that a certain synth is active during all the events, that would narrow it down I would think.
I'll try to run DP as administrator, though this is the first I've heard of that, and I have run it many times in the past. I'll probably end up reinstalling it.

BRainbow
I agree with Kev 999 that you should try freezing all your synth tracks...

 
That wasn't me. Freezing might actually mask the problem. If you freeze the synth that happens to be the one that is causing the hiss and it doesn't hiss during the freeze process, then you'll never know if that was the one. Also, freezing takes time whereas muting or soloing is one-click and instant.

I uninstalled and reinstalled Dim Pro last night, on the theory that perhaps Dim LE was the culprit. Also, I would rather have Dim Pro than LE anyway. That went fine, so far no noise. So I'm now using Dim Pro and have turned LE off. Until I get the noise again, that's my theory and I'm sticking to it. If it comes back, I'll continue troubleshooting, considering all the very helpful advice you folks have been giving me.
 
One thing I wonder about re: Dim Pro: I don't think I've ever got the DXI or 64-bit versions working. I always use the 32-bit version, which has always worked fine. Anyone have a different experience?

I'm actually using the New CbB as folks have decided to call it. That's 64-bit only, isn't it?
 
Re: Dim Pro, id the noise returns, I plan to reinstall again, this time installing both 32 and 64 bit versions. I should have just installed the 64 last night along with the 32. Oh well, some good hockey games on tonight....

If the noise comes back, just mute one track at a time until the noise goes away.
 
Then something on that last track muted or something it routes to,  is related to the noise.