I love my MacBook Pro. When they came out, I knew the fifteen inch, top-of-the-line MacBook Pro with an Intel Core Duo was my dream machine, and even though it took me a while to get one, I’ve never looked back. I’d suffered with a 700 pound eMac for so long that I’d forgotten how beautiful a Macintosh can be.

Fast-forward to late 2007 when I’ve graduated from college and somehow managed to acquire an income, an apartment, and a widescreen TV. My TV is also a thing of beauty. Thirty-two inches (which is the perfect size for my living space), 1080p high definition, and a gorgeous shining black surface. It’s a Sharp Aquos 32″ HDTV, and if you’re in the market for a television at that size, I highly recommend it. Beautiful picture, perfect for gaming (which is why I bought it), and the built-in speakers are quite good, as well, which is a major plus because I hate the neighbors thanks to their sound system, and wouldn’t wish to become what I despise.

With two such wonderful gadgets in my house, naturally I wanted them to get together, so I went out and bought an HDMI cable and an audio audio cable to connect the MacBook Pro to the TV. As best I can remember, it worked great the first few times I watched movies.

But the last couple times, as soon as I plugged in the audio cable, the TV started outputting a high-pitched whine through the speakers, which was extremely annoying.

I figured it might be the audio cable, but that didn’t make much sense; it was new and worked fine a few times. Magnetic interference seemed like a long shot, since there was nothing electronic nearby except the TV and the computer itself. Before I rushed off to buy a second audio cable, I decided to consult the internets.

After a little research online, I found there was some info about whining MacBook Pros, but it all had to do with the computer itself whining. Fortunately, Daniel Jalkut had quite a lot to say about CPU whining in MacBook Pros. I tried his QuietMBP program, and surprisingly, it fixed the whine through the television speakers.

Here’s where it gets fun: the QuietMBP program basically uses up idle time in the CPU by running pointless data through it. You can control how often the program runs stuff through the CPU with a slider, and you’re supposed to set the slider as high as you can to alleviate the noise (lower numbers = smaller gaps between CPU usage = more power consumption). I started dragging the slider, and the whine started changing pitch in real time.

Seriously, I could have played music with the damn thing. It was bizarre. Why the heck does a piece of software that’s supposed to help with CPU-related whining change a whine going through external speakers? Why have I never heard a whine through either my computer’s speakers or my trusty JBL Creatures? What god of electronics did I offend, anyway?

It’s baffling to me.

Now that I’m sensitized to the whine, though, I’m realizing that I do sometimes get a strange high-pitched whine when my MacBook Pro is running off battery. Why it took almost two years and a TV to bring this to my attention, I don’t know. Possibly because the eMac was basically a jet engine with a screen on it (think noise, not speed) and my ears have been ringing all this time.

In any case, if you’re experiencing problematic whining when you hook your MacBook Pro up to a pair of external speakers that otherwise behave well, it might not be your cable, your speakers, or really anything involved with getting audio from your Mac to the outside world. It might be your CPU.

Go figure.