Audio starts crackling while browsing after some time of computer usage.

Who makes the computer and did you got to the vendor website to see if there is a fix?
CT
 

It isn't a new computer, and I built it myself a long time ago. Vista has run fine on it for over a year before I reformated and got this problem.

Are you connecting wirelessly by any chance?
If yes, update the wireless card driver, or in the settings of the wireless card check what frequency it is using?

Nope. I'm plugged in.

Is the sound normal if you play a movie or anything? What happens if you watch something streaming, does it interfere with the sound

Anything that I do is just fine as long as I am not browsing. It only happens when I browse, whatever is playing, stream, movie, music, will start crackling until the webpage has loaded completely.

Does it happen with different browsers?

Yes, all of them.

Well, there is sound when you load webpages. It  sounds funny but normal on my computer.
Do you only hear the crackling sound when the pages are loading?
Check how you hear this sound:
Go to Start-Control Panel(Classic View)-click on Sounds icon-then click on the Sound tab-Scroll down untill you see "Windows Explorer"-The last option of it:"Start Navigation" is the sound type assigned to your computer for when the pages are loading-Click on the Start Navigation to mark it and then click on the "Test" button to hear the sound. Is that the sound you hear?
You can change what sound is played from the drop down menu below on the same window

Forgot. Additionally, to speed up internet pages loading in Vista, do the following:
Start-type: cmd in the search bar-right click on the cmd icon above and choose: Run as administrator-type in the black window opened:
netsh int tcp set global autotunning=disable
and then hit enter on the keyboard
Restart the computer

What is the motherboard?
Is sound on-board or an add-in?

Onboard has been disabled on the Asus Maximus Formula. I am using a Sondigo Inferno 7.1 soundcard.

I would suspect bad soldering or [more likely] cheap capacitors.

snazy: there's no sound when I load webpages, I have the windows sounds disabled -- it's just that whichever sound is playing from a video or music player will start crackling when I load webpages. As soon as the loading of the webpage is done, the crackling stops until I load a new page.

Does it do the same thing in other browsers?

OK, to summarize the problem:
-If you play any program with sound and load webpages at the same time you experience crackling sound, untill the page is loaded.
-It happens with any combination of playback program and webbrowser
-You only experience this after a couple of hours usage
-You only experience this with the current operating system, but not others
The above would suggest that when there is heavy network traffic(which leads to high memory usage) and sound played at the same time, it is when the crackling sound appears
Because it only happened it Vista, but not the previous OS, then it should be a sofware issue, like driver incopatibility.
Please do the following to troubleshoot:
-Disconnect the network cable when the crackling starts and then load internet pages to see if the issue is in explorer, or the network traffic it causes. If the issue is still the same, when cable disconnected, then you might have problem with memory may be.
-If it is the network traffic, I would start checking the ethernet cable and may be reinstall or update the sound and ethernet card driver where possible
-Because you said it happens after heavy browsing, I would check what the memory utilization is at the time. Do you have enough memory to operate, or maybe it is getting faulty(hot). Or maybe increase the paging file/swap file for virtual memory?

Well in reality, I was using Vista as well before, I only format/reinstalled it and it's been doing it since. I will try your suggestion with the network thing, but I am expecting it not to crackle since there are no webpages to load, it will just give me an error. I have 8GB of memory and many fans in my Antec 1200 case. I am thinking of trying a new sound card to see if that fixes the problem, it'll take a couple of days before I have one on my hands though.

So, I have tried using another soundcard but the soundcard ended up not working for me so I am back to trying to figure out what the hell is wrong here with this particular build. I can't afford spending money on a new soundcard just to test if that's the problem.

if you haven't tried this yet, disable the soundcard and switch to your onboard sound. if it's still doing it, then the problem likely isn't your soundcard or the driver for it. that might help get around the monetary obstacle in trying to determing if it's the card itself or not. if it's happening still with the onboard sound, then I would suspect that there's something going on with Vista itself, not the cards or the drivers.

it's a weird issue and one that's difficult to troubleshoot. I'm also having a very similar problem, except with an old Creative Sound Blaster Live! 24-bit PCI card on an ASUS M2N32-SLI board. only happens when i'm browsing, but once it starts it doesn't stop until a reboot. it's noticeably worse while the browser is active though. I only use iTunes for music playback.

someone came into the shop where I work a couple of months ago with a similar problem, but he said that his started when he upgraded from a single-core Athlon 64 processor to a dual-core Athlon X2. we reinstalled the soundcard drivers (it was onboard) and it seemed to fix the problem for him (though I'm only guessing that since he hasn't brought it back -- that doesn't mean it's fixed.) don't remember what kind of board he had, but it was a custom-built machine. I've tried reinstalling the drivers on mine, but no luck.

I seem to recall finding some info somewhere that indicated that the Cool'n'Quiet functionality in Athlon dual-core processors might have something to do with this, but I haven't had a lot of luck finding reliable info about it. i just searched and found someone who said that disabling CnQ solved his CTD problems with Eve Online and an ASUS AMD board with 3 different soundcards. I would maybe try disabling that in the BIOS of your Maximus and see if that helps at all.

I have an Intel processor so that can't be it. My BIOS options are also the same as they were when my Vista was running just fine for over a year.

I thought about the onboard thing but the problem is that I am plugged in optical on my soundcard. I'll try finding an RCA cable and testing it, thanks for your help!

Wow! I just figured out there was actually an optical plug on my onboard sound. I had no idea. I'm testing it right away.

ah right, I forgot the Striker is the AMD top-of-the-line and the Maximus is the Intel one.

yes, the nice thing about the high-end ASUS boards is they have optical sound outs and dual NICs on their boards. good luck.

Okay, I am plugged into my onboard and left my computer on overnight, came back and it's STILL doing it. So it's not a video card problem. It just has to be my hard drive. I'll test it with WD diag and I'll try migrating my OS to another HD, I think.

I mean not a sound card problem*

Run ground wires to that idiotic heat-piped together heat-sink contraption.
They used copper vs non-magnetic aluminum and thus it's acting like a huge multi-finned antenna sucking in EMI from every possible source.
The pipe even runs to the MOSFETs which are a HUGE source of EMI and the pipe carries it right to both the north and south bridges of the chipset.
At a minimum you need to ground it between the north bridge and the MOSFETs but I'd use at least one more ground at the other end of the MOSFETs.
You just need short lengths of wire with an eye/loop connector on each end.
Put one end under a mobo mounting screw and use another screw run-in between heatsink fins to attach the other end to the monstrosity.
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I'm extremely confused. You're telling me that the problem I am experiencing right now is due to the design of my motherboard?

Yes.
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When they use magnetic material to make fins it's like making dozens of sets of rabbit ears that will collect noise from any source including fans, drives, and PSU.
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Separate issue: MOSFETs give off LOADS of EMI. Even without fins the continuous nature of that heat pipe is spreading it all over the board including to your North Bridge. - Those parts of processing sound that need CPU and/or RAM pass right through the North Bridge regardless if you use on-board or add-in sound.

That heat pipe is for show.
From an engineering standpoint it's an atrocity.

You aren't the only one that's had EMI problems with that board.

Well that's definitely interesting. Taking that into consideration, can you explain why it is that I only get them after the same amount of time after my computer has been on and also explain why it happens progressively, as well as why it never happened in over 1 year of usage and now it suddenly does after a format? But more importantly, why does it happen only when I'm loading a web page? Certainly, if it was a motherboard/magnetism problem it wouldn't be this consistent with software problems?

The heat-up and cool down will play a huge part in 'lining things up' for the EMI problem to show up.

The software causes signals to pass through the north bridge where they pick up EMI.
Web page -> LAN activity through North Bridge.
Sound -> activity through North Bridge.

Capacitor aging will cause the MOSFETs to gradually get louder over time. [Make more noise.]
MOSFETs have a behavior called 'ringing'. Ringing radiates EMI.
MOSFETs that aren't well chosen or that have bad filter caps can ring loud enough that you can hear them.
At that point it's called "singing MOSFETs".

More heavily loaded MOSFETs will generate more noise.
You switched to Vista, which puts a heavier load on everything.
Power supplies, as they age, shift work-load to the MOSFETs.
Filter capacitors that are degraded [or even just aged] shift work-load to the MOSFETs.

Because the heat-pipe is continuous and connected to different areas that heat and coolat different rates and times from one another, expansion/contraction in one area will cause a shearing action between the heat sink and the device it's cooling in the another areas. Whatever heats the most pushes sideways by way of the the pipe getting longer [expanding]. The shearing action will break down and gradually thin [compress] the thermal paste (or pad) in between them. The thinning will cause the heat-sink [with the EMI in it] to get closer to the chip over time making it easier for EMI in the heat-sink to affect the chip(s). As well as making it easier at the MOSFETs for the EMI to get into the heat-sink in the first place. [The paste there is thinner too.]
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So that's why my north bridge temperatures are off the roof compared to everything else. Actually, I remembered that one time I came back on the computer and there had been an overheating failure related to the northbridge.

Anyway, I have experience building my own machines but I'm afraid you are being too advanced with me right now. Everything you said about the process was well detailed and it all makes sense (for what I understood of it) but I really can't picture what I would have to do or what materials I need. I've never messed around with a component before. I'm almost thinking of buying a new board if you're absolutely certain that this is my problem and solving it myself turns out to be too demanding for my skill level.

I ended up reinstalling windows on another hard drive. Problem hasn't resurfaced yet and I've been running this windows installation for 5 days. I'm guessing it was a hard drive problem.

What a strange problem and even more strange solution.

What are the speeds of the hard drives? EMI is still possible, but a change in RPM might avoid the audio frequencies.

Is heat still a problem? You may want to try re-applying thermal compound on the cooler to see if it helps.  It may also help if the noise problem returns.

Grounding is simply attaching a wire between locations, very easy and just needs a screwdriver and screws to secure both ends.

If the problem returns, try moving the speakers around (i.e. closer and farther away from different parts of the computer) and see if that makes any difference. EMI via air would be reduced the farther away the speakers, but if the noise is thru the speaker wire, then it wouldn't change.

Oh, wanted to mention that the reinstall of windows also refreshed/updated drivers, so it's possible the hard drive itself was fine.