A friend on Facebook posted a funny video of this cat that looks like Hedonism Bot on Futurama, or maybe Jabba the Hut, on Star Wars getting "pissed" because his food bowl is empty. I listened and listened, but I could hear nothing, so I set out to use science to prove her wrong.
Man, do I have egg on my face!!! She was right! After analyzing the sound track, and comparing the cats meow, I can see a definite, yet slight increase in amplitude of the meow, but no discernible change in meow frequency. I bet she is relieved to finally have the scientific data to back up what she said. Now she can sleep at night, without worrying all night long if someone is going to call her on it! You're welcome Kathy!
For completeness sake, the original video is here,