Hummingbird audio at 50% Speed is amazing!

Video I took using my phone in slow-motion mode. The video is kind of cool. But it's the audio that's amazing. All we hear is 'chirp-chirp' at normal speed, but slowed down, they are having a full-on conversation! I had no idea. I almost deleted the file because of its size before I listened to the audio. Question is. Are they moving at super high speed and talking at super high frequency. Or, are we doing the opposite of moving at slow speed and low frequency? It's all relative!