This is the internal speakers of the laptop. I've tried a lot of things, apparently it's a very common problem since I find it all over the internet. I've tried most of the wisdoms out there with no success.

It happens whenever I switch applications, and frequently when I update a browser screen. Buzzing for a second or two, then stops with a click. As if something were turning on and then off.

I have the latest Realtek HD audio driver from the Asus site and haven't tried a later version since that's the only one listed to work properly.

One of the things that I'm not sure of is Nvidia has two HD audio drivers as well. I don't think they are used? Pretty sure they are for external monitors with video and audio. I tried to disable them and it made no difference, but I didn't reboot in between so maybe I needed to do that? They are back to enabled right now since I saw no difference.

It seems to just be an "unavoidable" issue when using onboard audio - sometimes your chipset gets too busy and feeds some noise into the audio. Maybe the beefier onboard audio solutions on higher-end mobos tends to conceal the problem better. You probably get some audio stutter whenever "HDD LED" is lit.
Not too much you can do about it with a laptop mobo, except perhaps use an external audio device.

And some motherboards are "noisier" than others, the audio codec can apparently be just as variable and quirky as any other piece of silicon. I haven't done any proper comparisons with measuring instruments but I have definitely noticed differences on a few side-by-side comparisons between "identical" platforms. Also note that Realtek chips contain built-in DRM features, I'm not sure how (or even if) this audio DRM is activated but if it is then (as always) it will impose extra layers of complexity which will limit performance or quality in peak-demand situations.
Again, dedicated audio hardware (which has it's own filters and buffers and stuff) can mitigate a lot of audio problems.

Intel CPUs have a dedicated HD Audio "channel" serviced by the chipset (Intel PCH and chipset add-on Realtek audio part connected downstream to it). GPU cards communicate with the CPU to fetch audio signals, and use their own drivers to translate it, because they can carry audio through their HDMI or DP outputs. You don't strictly need to install those software components if you're not using those hardware functions, although their horrible driver packages might force it all onto you anyhow. Clean audio can be disrupted or deprioritized when the CPU-to-PCH (DMI bus) bandwidth or the CPU-to-GPU (PCIe3 bus) bandwidth gets saturated with other data.

If it's only a mild annoyance then you'll just have to be mildly annoyed, lol. If it's a major annoyance then you won't regret buying decent headphones (basically anything $100+ which isn't Skullcandy or Beats by Dre) and a decent external audio device (like an O2+ODAC or a FiiO E10K) - the added bonus is that these can be "installed" without any software/drivers at all on any kind of machine which has a USB port.

Korth, I can always rely on you my friend for a thorough well thought-out response. 😄 Thanks!

I should've probably mentioned the following in the OP
- This problem never occurs when I am sending digital audio through my receiver when I use the TV screen to duplicate my video and the sound goes across HDMI to the home theater.
- This problem never occurs through my headphones either (I have a good gaming set).
- This problem does not occur during playback of audio, such as videos or games, only at the beginning and end.
- This problem does occur when audio is commanded to start, and also when there's no sound being used (such as switching a webpage).

This issue never existed as I recall when I first bought this laptop. And I've upgraded the Realtek drivers one time since then. Perhaps I'll try a rollback to the previous version to see if it goes back into the black hole from whence it came.