I have a cat. A cranky old cat, who sleeps on my desk because it’s warm under the lamp, and who has been known to walk across my key board. Thus, when someone sent me a link to this link, I viewed it with a flicker of interest. PawSense: Cat Proof Your Computer.
It’s a software utility that recognizes “cat-like typingâ€� and does two things. First, it plays a WAV file that (supposedly) annoys cats — the implication being that they’d then go away. Second, it freezes keyboard input and throws up this screen.

So I tested it. My cat lay on my desk next to me, snoring and occasionally batting irritably at my arm when my movement disturbed her slumbers. I turned up my speakers and played the first of the two special cat-annoying WAV files, watching her carefully.
No response. From her, that is. I myself found the discordant-harmonica noise very annoying.
Then I played the second cat-annoying sound, the hissing noise.
Nothing. She didn’t so much as crack an eye. I strongly doubt she’d respond to it even if she were strolling across my keyboard. PawSense claims you can also record your own noises, but I can’t believe that would do any good. Rammstein, the 1812 Overture, dogs barking, whatever, no mere WAV file would deter my cat from her chosen path. So that was pretty much a bust.
And frankly, I’m not sure my typing is always so reliably human-like. Some days it’s hard enough staying confident about yourself as a writer without having some software program constantly questioning whether you have opposable thumbs.